ASP.NET (snapshot 2017) Microsoft documentation and samples

Migrating HTTP handlers and modules to ASP.NET Core middleware

This article shows how to migrate existing ASP.NET HTTP modules and handlers from system.webserver to ASP.NET Core middleware.

Modules and handlers revisited

Before proceeding to ASP.NET Core middleware, let’s first recap how HTTP modules and handlers work:

Handlers are:

Classes that implement IHttpHandler
Used to handle requests with a given file name or extension, such as .report
Configured in Web.config

Modules are:

Classes that implement IHttpModule
Invoked for every request
Able to short-circuit (stop further processing of a request)
Able to add to the HTTP response, or create their own
Configured in Web.config

The order in which modules process incoming requests is determined by:

The application life cycle, which is a series events fired by ASP.NET: BeginRequest, AuthenticateRequest, etc. Each module can create a handler for one or more events.
For the same event, the order in which they are configured in Web.config.

In addition to modules, you can add handlers for the life cycle events to your Global.asax.cs file. These handlers run after the handlers in the configured modules.

From handlers and modules to middleware

Middleware are simpler than HTTP modules and handlers:

Modules, handlers, Global.asax.cs, Web.config (except for IIS configuration) and the application life cycle are gone
The roles of both modules and handlers have been taken over by middleware
Middleware are configured using code rather than in Web.config
Pipeline branching lets you send requests to specific middleware, based on not only the URL but also on request headers, query strings, etc.

Middleware are very similar to modules:

Invoked in principle for every request
Able to short-circuit a request, by not passing the request to the next middleware
Able to create their own HTTP response

Middleware and modules are processed in a different order:

Order of middleware is based on the order in which they are inserted into the request pipeline, while order of modules is mainly based on application life cycle events
Order of middleware for responses is the reverse from that for requests, while order of modules is the same for requests and responses
See Creating a middleware pipeline with IApplicationBuilder

Note how in the image above, the authentication middleware short-circuited the request.

Migrating module code to middleware

An existing HTTP module will look similar to this:

[!code-csharpMain]

   1:  // ASP.NET 4 module

2:

   3:  using System;

   4:  using System.Web;

5:

   6:  namespace MyApp.Modules

   7:  {

   8:      public class MyModule : IHttpModule

   9:      {

  10:          public void Dispose()

  11:          {

  12:          }

13:

  14:          public void Init(HttpApplication application)

  15:          {

  16:              application.BeginRequest += (new EventHandler(this.Application_BeginRequest));

  17:              application.EndRequest += (new EventHandler(this.Application_EndRequest));

  18:          }

19:

  20:          private void Application_BeginRequest(Object source, EventArgs e)

  21:          {

  22:              HttpContext context = ((HttpApplication)source).Context;

23:

  24:              // Do something with context near the beginning of request processing.

  25:          }

26:

  27:          private void Application_EndRequest(Object source, EventArgs e)

  28:          {

  29:              HttpContext context = ((HttpApplication)source).Context;

30:

  31:              // Do something with context near the end of request processing.

  32:          }

  33:      }

  34:  }

As shown in the Middleware page, an ASP.NET Core middleware is a class that exposes an Invoke method taking an HttpContext and returning a Task. Your new middleware will look like this:

[!code-csharpMain]

   1:  // ASP.NET Core middleware

2:

   3:  using Microsoft.AspNetCore.Builder;

   4:  using Microsoft.AspNetCore.Http;

   5:  using System.Threading.Tasks;

6:

   7:  namespace MyApp.Middleware

   8:  {

   9:      public class MyMiddleware

  10:      {

  11:          private readonly RequestDelegate _next;

12:

  13:          public MyMiddleware(RequestDelegate next)

  14:          {

  15:              _next = next;

  16:          }

17:

  18:          public async Task Invoke(HttpContext context)

  19:          {

  20:              // Do something with context near the beginning of request processing.

21:

  22:              await _next.Invoke(context);

23:

  24:              // Clean up.

  25:          }

  26:      }

27:

  28:      public static class MyMiddlewareExtensions

  29:      {

  30:          public static IApplicationBuilder UseMyMiddleware(this IApplicationBuilder builder)

  31:          {

  32:              return builder.UseMiddleware<MyMiddleware>();

  33:          }

  34:      }

  35:  }

The above middleware template was taken from the section on writing middleware.

The MyMiddlewareExtensions helper class makes it easier to configure your middleware in your Startup class. The UseMyMiddleware method adds your middleware class to the request pipeline. Services required by the middleware get injected in the middleware’s constructor.

Your module might terminate a request, for example if the user is not authorized:

[!code-csharpMain]

   1:  using System;

   2:  using System.Web;

3:

   4:  namespace MyApp.Modules

   5:  {

   6:      public class MyTerminatingModule : IHttpModule

   7:      {

   8:          public void Dispose()

   9:          {

  10:          }

11:

  12:          public void Init(HttpApplication application)

  13:          {

  14:              application.BeginRequest += (new EventHandler(this.Application_BeginRequest));

  15:              application.EndRequest += (new EventHandler(this.Application_EndRequest));

  16:          }

17:

  18:          #region snippet_Terminate

  19:          // ASP.NET 4 module that may terminate the request

20:

  21:          private void Application_BeginRequest(Object source, EventArgs e)

  22:          {

  23:              HttpContext context = ((HttpApplication)source).Context;

24:

  25:              // Do something with context near the beginning of request processing.

26:

  27:              if (TerminateRequest())

  28:              {

  29:                  context.Response.End();

  30:                  return;

  31:              }

  32:          }

  33:          #endregion

34:

  35:          private void Application_EndRequest(Object source, EventArgs e)

  36:          {

  37:              HttpContext context = ((HttpApplication)source).Context;

38:

  39:              // Do something with context near the end of request processing.

  40:          }

41:

  42:          private bool TerminateRequest()

  43:          {

  44:              return false;

  45:          }

  46:      }

  47:  }

A middleware handles this by not calling Invoke on the next middleware in the pipeline. Keep in mind that this does not fully terminate the request, because previous middlewares will still be invoked when the response makes its way back through the pipeline.

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Threading.Tasks;

4:

   5:  namespace MyApp.Middleware

   6:  {

   7:      public class MyTerminatingMiddleware

   8:      {

   9:          private readonly RequestDelegate _next;

10:

  11:          public MyTerminatingMiddleware(RequestDelegate next)

  12:          {

  13:              _next = next;

  14:          }

15:

  16:          #region snippet_Terminate

  17:          // ASP.NET Core middleware that may terminate the request

18:

  19:          public async Task Invoke(HttpContext context)

  20:          {

  21:              // Do something with context near the beginning of request processing.

22:

  23:              if (!TerminateRequest())

  24:                  await _next.Invoke(context);

25:

  26:              // Clean up.

  27:          }

  28:          #endregion

29:

  30:          private bool TerminateRequest()

  31:          {

  32:              return false;

  33:          }

  34:      }

35:

  36:      public static class MyTerminatingMiddlewareExtensions

  37:      {

  38:          public static IApplicationBuilder UseMyTerminatingMiddleware(this IApplicationBuilder builder)

  39:          {

  40:              return builder.UseMiddleware<MyTerminatingMiddleware>();

  41:          }

  42:      }

  43:  }

When you migrate your module’s functionality to your new middleware, you may find that your code doesn’t compile because the HttpContext class has significantly changed in ASP.NET Core. Later on, you’ll see how to migrate to the new ASP.NET Core HttpContext.

Migrating module insertion into the request pipeline

HTTP modules are typically added to the request pipeline using Web.config:

[!code-xml 1:

   2:    3:    4:    5:      6:      7:      8:      9:   10:   11:     12:     13:     14:   15:   16:     17:     18:     19:     20:     21:   22:   23:     24:     25:     26:   27:     28:     29:     30:     31:   32:   33:     34:     35:   36:     37:     38:     39:     40:     41:     42:   43:     44:   45:     46:     47:     48:     49:     50:   51:   52:     53:     54:     55:     56:     57:     58:     59:     60:     61:     62:     63:     64:     65:     66:     67:     68:     69:     70:     71:     72:     73:     74:     75:     76:     77:     78:     79:     80:     81:     82:     83:     84:     85:     86:     87:     88:     89:     90:     91:     92:     93:     94:   95:   96:     97:     98:     99:    100:  101:

odules/sample/Asp.Net4/Asp.Net4/Web.config?highlight=6&range=1-3,32-33,36,43,50,101">Main]

<?xml version="1.0" encoding="utf-8"?>  <configuration> <configSections> <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/> </configSections> <connectionStrings> <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\aspnet-Asp.Net4-20160127091227.mdf;Initial Catalog=aspnet-Asp.Net4-20160127091227;Integrated Security=True" providerName="System.Data.SqlClient"/> </connectionStrings> <appSettings> <add key="owin:AutomaticAppStartup" value="false"/> <add key="webpages:Version" value="3.0.0.0"/> <add key="webpages:Enabled" value="false"/> <add key="ClientValidationEnabled" value="true"/> <add key="UnobtrusiveJavaScriptEnabled" value="true"/> </appSettings> <system.web> <authentication mode="None"/> <compilation debug="true" targetFramework="4.6"/> <httpRuntime targetFramework="4.6"/> <httpHandlers> <add path="*.report" verb="*" type="Asp.Net4.HttpHandlers.ReportHandler"/> </httpHandlers> </system.web> <system.webServer> <modules> <remove name="FormsAuthentication"/> <add name="MyModule" type="MyApp.Modules.MyModule"/> <add name="MyTerminatingModule" type="MyApp.Modules.MyTerminatingModule"/> </modules> <validation validateIntegratedModeConfiguration="false"/> <handlers> <add name="MyHandler" verb="*" path="*.report" type="MyApp.HttpHandlers.MyHandler" resourceType="Unspecified" preCondition="integratedMode"/> </handlers> </system.webServer> <runtime> <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"> <dependentAssembly> <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed"/> <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0"/> </dependentAssembly> <dependentAssembly> <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35"/> <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/> </dependentAssembly> </assemblyBinding> </runtime> <entityFramework> <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/> <providers> <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/> </providers> </entityFramework> </configuration>

Convert this by adding your new middleware to the request pipeline in your Startup class:

[!code-csharpMain]

   1:  // ASP.NET Core Startup class

2:

   3:  using System;

   4:  using System.Collections.Generic;

   5:  using System.Linq;

   6:  using System.Threading.Tasks;

   7:  using Microsoft.AspNetCore.Builder;

   8:  using Microsoft.AspNetCore.Hosting;

   9:  using Microsoft.Extensions.Configuration;

  10:  using Microsoft.Extensions.DependencyInjection;

  11:  using Microsoft.Extensions.Logging;

  12:  using MyApp.Middleware;

13:

  14:  namespace Asp.Net.Core

  15:  {

  16:      public class Startup

  17:      {

  18:          #region snippet_Ctor

  19:          public Startup(IHostingEnvironment env)

  20:          {

  21:              var builder = new ConfigurationBuilder()

  22:                  .SetBasePath(env.ContentRootPath)

  23:                  .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

  24:                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

  25:                  .AddEnvironmentVariables();

  26:              Configuration = builder.Build();

  27:          }

  28:          #endregion

29:

  30:          public IConfigurationRoot Configuration { get; }

31:

  32:          // This method gets called by the runtime. Use this method to add services to the container.

  33:          #region snippet_ConfigureServices

  34:          public void ConfigureServices(IServiceCollection services)

  35:          {

  36:              // Setup options service

  37:              services.AddOptions();

38:

  39:              // Load options from section "MyMiddlewareOptionsSection"

  40:              services.Configure<MyMiddlewareOptions>(

  41:                  Configuration.GetSection("MyMiddlewareOptionsSection"));

42:

  43:              // Add framework services.

  44:              services.AddMvc();

  45:          }

  46:          #endregion

47:

  48:          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

  49:          #region snippet_Configure

  50:          public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

  51:          {

  52:              loggerFactory.AddConsole(Configuration.GetSection("Logging"));

  53:              loggerFactory.AddDebug();

54:

  55:              if (env.IsDevelopment())

  56:              {

  57:                  app.UseDeveloperExceptionPage();

  58:                  app.UseBrowserLink();

  59:              }

  60:              else

  61:              {

  62:                  app.UseExceptionHandler("/Home/Error");

  63:              }

64:

  65:              app.UseMyMiddleware();

66:

  67:              app.UseMyMiddlewareWithParams();

68:

  69:              var myMiddlewareOptions = Configuration.GetSection("MyMiddlewareOptionsSection").Get<MyMiddlewareOptions>();

  70:              var myMiddlewareOptions2 = Configuration.GetSection("MyMiddlewareOptionsSection2").Get<MyMiddlewareOptions>();

  71:              app.UseMyMiddlewareWithParams(myMiddlewareOptions);

  72:              app.UseMyMiddlewareWithParams(myMiddlewareOptions2);

73:

  74:              app.UseMyTerminatingMiddleware();

75:

  76:              // Create branch to the MyHandlerMiddleware.

  77:              // All requests ending in .report will follow this branch.

  78:              app.MapWhen(

  79:                  context => context.Request.Path.ToString().EndsWith(".report"),

  80:                  appBranch => {

  81:                      // ... optionally add more middleware to this branch

  82:                      appBranch.UseMyHandler();

  83:                  });

84:

  85:              app.MapWhen(

  86:                  context => context.Request.Path.ToString().EndsWith(".context"),

  87:                  appBranch => {

  88:                      appBranch.UseHttpContextDemoMiddleware();

  89:                  });

90:

  91:              app.UseStaticFiles();

92:

  93:              app.UseMvc(routes =>

  94:              {

  95:                  routes.MapRoute(

  96:                      name: "default",

  97:                      template: "{controller=Home}/{action=Index}/{id?}");

  98:              });

  99:          }

 100:          #endregion

 101:      }

 102:  }

 103:

 104:

 105:

 106:

 107:

 108:

 109:

 110:

 111:

 112:

 113:

 114:

 115:

 116:

 117:

 118:

 119:

 120:

 121:

 122:

 123:  //

The exact spot in the pipeline where you insert your new middleware depends on the event that it handled as a module (BeginRequest, EndRequest, etc.) and its order in your list of modules in Web.config.

As previously stated, there is no application life cycle in ASP.NET Core and the order in which responses are processed by middleware differs from the order used by modules. This could make your ordering decision more challenging.

If ordering becomes a problem, you could split your module into multiple middleware components that can be ordered independently.

Migrating handler code to middleware

An HTTP handler looks something like this:

[!code-csharpMain]

   1:  // ASP.NET 4 handler

2:

   3:  using System.Web;

4:

   5:  namespace MyApp.HttpHandlers

   6:  {

   7:      public class MyHandler : IHttpHandler

   8:      {

   9:          public bool IsReusable { get { return true; } }

10:

  11:          public void ProcessRequest(HttpContext context)

  12:          {

  13:              string response = GenerateResponse(context);

14:

  15:              context.Response.ContentType = GetContentType();

  16:              context.Response.Output.Write(response);

  17:          }

18:

  19:          // ...

20:

  21:          private string GenerateResponse(HttpContext context)

  22:          {

  23:              string title = context.Request.QueryString["title"];

  24:              return string.Format("Title of the report: {0}", title);

  25:          }

26:

  27:          private string GetContentType()

  28:          {

  29:              return "text/plain";

  30:          }

  31:      }

  32:  }

In your ASP.NET Core project, you would translate this to a middleware similar to this:

[!code-csharpMain]

   1:  // ASP.NET Core middleware migrated from a handler

2:

   3:  using Microsoft.AspNetCore.Builder;

   4:  using Microsoft.AspNetCore.Http;

   5:  using System.Threading.Tasks;

6:

   7:  namespace MyApp.Middleware

   8:  {

   9:      public class MyHandlerMiddleware

  10:      {

11:

  12:          // Must have constructor with this signature, otherwise exception at run time

  13:          public MyHandlerMiddleware(RequestDelegate next)

  14:          {

  15:              // This is an HTTP Handler, so no need to store next

  16:          }

17:

  18:          public async Task Invoke(HttpContext context)

  19:          {

  20:              string response = GenerateResponse(context);

21:

  22:              context.Response.ContentType = GetContentType();

  23:              await context.Response.WriteAsync(response);

  24:          }

25:

  26:          // ...

27:

  28:          private string GenerateResponse(HttpContext context)

  29:          {

  30:              string title = context.Request.Query["title"];

  31:              return string.Format("Title of the report: {0}", title);

  32:          }

33:

  34:          private string GetContentType()

  35:          {

  36:              return "text/plain";

  37:          }

  38:      }

39:

  40:      public static class MyHandlerExtensions

  41:      {

  42:          public static IApplicationBuilder UseMyHandler(this IApplicationBuilder builder)

  43:          {

  44:              return builder.UseMiddleware<MyHandlerMiddleware>();

  45:          }

  46:      }

  47:  }

48:

This middleware is very similar to the middleware corresponding to modules. The only real difference is that here there is no call to _next.Invoke(context). That makes sense, because the handler is at the end of the request pipeline, so there will be no next middleware to invoke.

Migrating handler insertion into the request pipeline

Configuring an HTTP handler is done in Web.config and looks something like this:

[!code-xmlMain]

   1:  <?xml version="1.0" encoding="utf-8"?>

   2:  <!--ASP.NET 4 web.config-->

   3:  <configuration>

   4:    <configSections>

5:

   6:      <section name="entityFramework"

   7:        type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"

   8:        requirePermission="false"/>

   9:    </configSections>

  10:    <connectionStrings>

  11:      <add name="DefaultConnection"

  12:        connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\aspnet-Asp.Net4-20160127091227.mdf;Initial Catalog=aspnet-Asp.Net4-20160127091227;Integrated Security=True"

  13:        providerName="System.Data.SqlClient"/>

  14:    </connectionStrings>

  15:    <appSettings>

  16:      <add key="owin:AutomaticAppStartup" value="false"/>

  17:      <add key="webpages:Version" value="3.0.0.0"/>

  18:      <add key="webpages:Enabled" value="false"/>

  19:      <add key="ClientValidationEnabled" value="true"/>

  20:      <add key="UnobtrusiveJavaScriptEnabled" value="true"/>

  21:    </appSettings>

  22:    <system.web>

  23:      <authentication mode="None"/>

  24:      <compilation debug="true" targetFramework="4.6"/>

  25:      <httpRuntime targetFramework="4.6"/>

26:

  27:      <httpHandlers>

  28:        <add path="*.report" verb="*" type="Asp.Net4.HttpHandlers.ReportHandler"/>

  29:      </httpHandlers>

30:

  31:    </system.web>

  32:    <system.webServer>

  33:      <modules>

  34:        <remove name="FormsAuthentication"/>

35:

  36:        <add name="MyModule" type="MyApp.Modules.MyModule"/>

37:

  38:        <add name="MyTerminatingModule" type="MyApp.Modules.MyTerminatingModule"/>

39:

40:

41:

42:

  43:      </modules>

44:

  45:      <validation validateIntegratedModeConfiguration="false"/>

  46:      <handlers>

  47:        <add name="MyHandler" verb="*" path="*.report" type="MyApp.HttpHandlers.MyHandler" resourceType="Unspecified" preCondition="integratedMode"/>

  48:      </handlers>

49:

  50:    </system.webServer>

  51:    <runtime>

  52:      <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">

  53:        <dependentAssembly>

  54:          <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35"/>

  55:          <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/>

  56:        </dependentAssembly>

  57:        <dependentAssembly>

  58:          <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35"/>

  59:          <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/>

  60:        </dependentAssembly>

  61:        <dependentAssembly>

  62:          <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35"/>

  63:          <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/>

  64:        </dependentAssembly>

  65:        <dependentAssembly>

  66:          <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35"/>

  67:          <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0"/>

  68:        </dependentAssembly>

  69:        <dependentAssembly>

  70:          <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed"/>

  71:          <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0"/>

  72:        </dependentAssembly>

  73:        <dependentAssembly>

  74:          <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35"/>

  75:          <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0"/>

  76:        </dependentAssembly>

  77:        <dependentAssembly>

  78:          <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35"/>

  79:          <bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234"/>

  80:        </dependentAssembly>

  81:        <dependentAssembly>

  82:          <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35"/>

  83:          <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>

  84:        </dependentAssembly>

  85:        <dependentAssembly>

  86:          <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35"/>

  87:          <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0"/>

  88:        </dependentAssembly>

  89:        <dependentAssembly>

  90:          <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35"/>

  91:          <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>

  92:        </dependentAssembly>

  93:      </assemblyBinding>

  94:    </runtime>

  95:    <entityFramework>

  96:      <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>

  97:      <providers>

  98:        <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>

  99:      </providers>

 100:    </entityFramework>

 101:  </configuration>

You could convert this by adding your new handler middleware to the request pipeline in your Startup class, similar to middleware converted from modules. The problem with that approach is that it would send all requests to your new handler middleware. However, you only want requests with a given extension to reach your middleware. That would give you the same functionality you had with your HTTP handler.

One solution is to branch the pipeline for requests with a given extension, using the MapWhen extension method. You do this in the same Configure method where you add the other middleware:

[!code-csharpMain]

   1:  // ASP.NET Core Startup class

2:

   3:  using System;

   4:  using System.Collections.Generic;

   5:  using System.Linq;

   6:  using System.Threading.Tasks;

   7:  using Microsoft.AspNetCore.Builder;

   8:  using Microsoft.AspNetCore.Hosting;

   9:  using Microsoft.Extensions.Configuration;

  10:  using Microsoft.Extensions.DependencyInjection;

  11:  using Microsoft.Extensions.Logging;

  12:  using MyApp.Middleware;

13:

  14:  namespace Asp.Net.Core

  15:  {

  16:      public class Startup

  17:      {

  18:          #region snippet_Ctor

  19:          public Startup(IHostingEnvironment env)

  20:          {

  21:              var builder = new ConfigurationBuilder()

  22:                  .SetBasePath(env.ContentRootPath)

  23:                  .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

  24:                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

  25:                  .AddEnvironmentVariables();

  26:              Configuration = builder.Build();

  27:          }

  28:          #endregion

29:

  30:          public IConfigurationRoot Configuration { get; }

31:

  32:          // This method gets called by the runtime. Use this method to add services to the container.

  33:          #region snippet_ConfigureServices

  34:          public void ConfigureServices(IServiceCollection services)

  35:          {

  36:              // Setup options service

  37:              services.AddOptions();

38:

  39:              // Load options from section "MyMiddlewareOptionsSection"

  40:              services.Configure<MyMiddlewareOptions>(

  41:                  Configuration.GetSection("MyMiddlewareOptionsSection"));

42:

  43:              // Add framework services.

  44:              services.AddMvc();

  45:          }

  46:          #endregion

47:

  48:          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

  49:          #region snippet_Configure

  50:          public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

  51:          {

  52:              loggerFactory.AddConsole(Configuration.GetSection("Logging"));

  53:              loggerFactory.AddDebug();

54:

  55:              if (env.IsDevelopment())

  56:              {

  57:                  app.UseDeveloperExceptionPage();

  58:                  app.UseBrowserLink();

  59:              }

  60:              else

  61:              {

  62:                  app.UseExceptionHandler("/Home/Error");

  63:              }

64:

  65:              app.UseMyMiddleware();

66:

  67:              app.UseMyMiddlewareWithParams();

68:

  69:              var myMiddlewareOptions = Configuration.GetSection("MyMiddlewareOptionsSection").Get<MyMiddlewareOptions>();

  70:              var myMiddlewareOptions2 = Configuration.GetSection("MyMiddlewareOptionsSection2").Get<MyMiddlewareOptions>();

  71:              app.UseMyMiddlewareWithParams(myMiddlewareOptions);

  72:              app.UseMyMiddlewareWithParams(myMiddlewareOptions2);

73:

  74:              app.UseMyTerminatingMiddleware();

75:

  76:              // Create branch to the MyHandlerMiddleware.

  77:              // All requests ending in .report will follow this branch.

  78:              app.MapWhen(

  79:                  context => context.Request.Path.ToString().EndsWith(".report"),

  80:                  appBranch => {

  81:                      // ... optionally add more middleware to this branch

  82:                      appBranch.UseMyHandler();

  83:                  });

84:

  85:              app.MapWhen(

  86:                  context => context.Request.Path.ToString().EndsWith(".context"),

  87:                  appBranch => {

  88:                      appBranch.UseHttpContextDemoMiddleware();

  89:                  });

90:

  91:              app.UseStaticFiles();

92:

  93:              app.UseMvc(routes =>

  94:              {

  95:                  routes.MapRoute(

  96:                      name: "default",

  97:                      template: "{controller=Home}/{action=Index}/{id?}");

  98:              });

  99:          }

 100:          #endregion

 101:      }

 102:  }

 103:

 104:

 105:

 106:

 107:

 108:

 109:

 110:

 111:

 112:

 113:

 114:

 115:

 116:

 117:

 118:

 119:

 120:

 121:

 122:

 123:  //

MapWhen takes these parameters:

A lambda that takes the HttpContext and returns true if the request should go down the branch. This means you can branch requests not just based on their extension, but also on request headers, query string parameters, etc.
A lambda that takes an IApplicationBuilder and adds all the middleware for the branch. This means you can add additional middleware to the branch in front of your handler middleware.

Middleware added to the pipeline before the branch will be invoked on all requests; the branch will have no impact on them.

Loading middleware options using the options pattern

Some modules and handlers have configuration options that are stored in Web.config. However, in ASP.NET Core a new configuration model is used in place of Web.config.

The new (xref:)configuration system gives you these options to solve this:

Directly inject the options into the middleware, as shown in the next section.
Use the (xref:)options pattern:

Create a class to hold your middleware options, for example:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using Microsoft.Extensions.Options;

   4:  using System.Threading.Tasks;

5:

   6:  namespace MyApp.Middleware

   7:  {

   8:      #region snippet_Options

   9:      public class MyMiddlewareOptions

  10:      {

  11:          public string Param1 { get; set; }

  12:          public string Param2 { get; set; }

  13:      }

  14:      #endregion

15:

  16:      #region snippet_MiddlewareWithParams

  17:      public class MyMiddlewareWithParams

  18:      {

  19:          private readonly RequestDelegate _next;

  20:          private readonly MyMiddlewareOptions _myMiddlewareOptions;

21:

  22:          public MyMiddlewareWithParams(RequestDelegate next,

  23:              IOptions<MyMiddlewareOptions> optionsAccessor)

  24:          {

  25:              _next = next;

  26:              _myMiddlewareOptions = optionsAccessor.Value;

  27:          }

28:

  29:          public async Task Invoke(HttpContext context)

  30:          {

  31:              // Do something with context near the beginning of request processing

  32:              // using configuration in _myMiddlewareOptions

33:

  34:              await _next.Invoke(context);

35:

  36:              // Do something with context near the end of request processing

  37:              // using configuration in _myMiddlewareOptions

  38:          }

  39:      }

  40:      #endregion

41:

  42:      #region snippet_Extensions

  43:      public static class MyMiddlewareWithParamsExtensions

  44:      {

  45:          public static IApplicationBuilder UseMyMiddlewareWithParams(

  46:              this IApplicationBuilder builder)

  47:          {

  48:              return builder.UseMiddleware<MyMiddlewareWithParams>();

  49:          }

50:

  51:          public static IApplicationBuilder UseMyMiddlewareWithParams(

  52:              this IApplicationBuilder builder, MyMiddlewareOptions myMiddlewareOptions)

  53:          {

  54:              return builder.UseMiddleware<MyMiddlewareWithParams>(

  55:                  new OptionsWrapper<MyMiddlewareOptions>(myMiddlewareOptions));

  56:          }

  57:      }

  58:      #endregion

  59:  }

Store the option values

The configuration system allows you to store option values anywhere you want. However, most sites use appsettings.json, so we’ll take that approach:

[!code-jsonMain]

   1:  {

   2:    "Logging": {

   3:      "IncludeScopes": false,

   4:      "LogLevel": {

   5:        "Default": "Debug",

   6:        "System": "Information",

   7:        "Microsoft": "Information"

   8:      }

   9:    },

  10:    "MyMiddlewareOptionsSection2": {

  11:      "Param1": "Param1Value2",

  12:      "Param2": "Param2Value2"

  13:    },

  14:    "MyMiddlewareOptionsSection": {

  15:      "Param1": "Param1Value",

  16:      "Param2": "Param2Value"

  17:    }

  18:  }

MyMiddlewareOptionsSection here is a section name. It doesn’t have to be the same as the name of your options class.

Associate the option values with the options class

The options pattern uses ASP.NET Core’s dependency injection framework to associate the options type (such as MyMiddlewareOptions) with a MyMiddlewareOptions object that has the actual options.

Update your Startup class:

If you’re using appsettings.json, add it to the configuration builder in the Startup constructor:

[!code-csharpMain]

   1:  // ASP.NET Core Startup class

2:

   3:  using System;

   4:  using System.Collections.Generic;

   5:  using System.Linq;

   6:  using System.Threading.Tasks;

   7:  using Microsoft.AspNetCore.Builder;

   8:  using Microsoft.AspNetCore.Hosting;

   9:  using Microsoft.Extensions.Configuration;

  10:  using Microsoft.Extensions.DependencyInjection;

  11:  using Microsoft.Extensions.Logging;

  12:  using MyApp.Middleware;

13:

  14:  namespace Asp.Net.Core

  15:  {

  16:      public class Startup

  17:      {

  18:          #region snippet_Ctor

  19:          public Startup(IHostingEnvironment env)

  20:          {

  21:              var builder = new ConfigurationBuilder()

  22:                  .SetBasePath(env.ContentRootPath)

  23:                  .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

  24:                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

  25:                  .AddEnvironmentVariables();

  26:              Configuration = builder.Build();

  27:          }

  28:          #endregion

29:

  30:          public IConfigurationRoot Configuration { get; }

31:

  32:          // This method gets called by the runtime. Use this method to add services to the container.

  33:          #region snippet_ConfigureServices

  34:          public void ConfigureServices(IServiceCollection services)

  35:          {

  36:              // Setup options service

  37:              services.AddOptions();

38:

  39:              // Load options from section "MyMiddlewareOptionsSection"

  40:              services.Configure<MyMiddlewareOptions>(

  41:                  Configuration.GetSection("MyMiddlewareOptionsSection"));

42:

  43:              // Add framework services.

  44:              services.AddMvc();

  45:          }

  46:          #endregion

47:

  48:          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

  49:          #region snippet_Configure

  50:          public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

  51:          {

  52:              loggerFactory.AddConsole(Configuration.GetSection("Logging"));

  53:              loggerFactory.AddDebug();

54:

  55:              if (env.IsDevelopment())

  56:              {

  57:                  app.UseDeveloperExceptionPage();

  58:                  app.UseBrowserLink();

  59:              }

  60:              else

  61:              {

  62:                  app.UseExceptionHandler("/Home/Error");

  63:              }

64:

  65:              app.UseMyMiddleware();

66:

  67:              app.UseMyMiddlewareWithParams();

68:

  69:              var myMiddlewareOptions = Configuration.GetSection("MyMiddlewareOptionsSection").Get<MyMiddlewareOptions>();

  70:              var myMiddlewareOptions2 = Configuration.GetSection("MyMiddlewareOptionsSection2").Get<MyMiddlewareOptions>();

  71:              app.UseMyMiddlewareWithParams(myMiddlewareOptions);

  72:              app.UseMyMiddlewareWithParams(myMiddlewareOptions2);

73:

  74:              app.UseMyTerminatingMiddleware();

75:

  76:              // Create branch to the MyHandlerMiddleware.

  77:              // All requests ending in .report will follow this branch.

  78:              app.MapWhen(

  79:                  context => context.Request.Path.ToString().EndsWith(".report"),

  80:                  appBranch => {

  81:                      // ... optionally add more middleware to this branch

  82:                      appBranch.UseMyHandler();

  83:                  });

84:

  85:              app.MapWhen(

  86:                  context => context.Request.Path.ToString().EndsWith(".context"),

  87:                  appBranch => {

  88:                      appBranch.UseHttpContextDemoMiddleware();

  89:                  });

90:

  91:              app.UseStaticFiles();

92:

  93:              app.UseMvc(routes =>

  94:              {

  95:                  routes.MapRoute(

  96:                      name: "default",

  97:                      template: "{controller=Home}/{action=Index}/{id?}");

  98:              });

  99:          }

 100:          #endregion

 101:      }

 102:  }

 103:

 104:

 105:

 106:

 107:

 108:

 109:

 110:

 111:

 112:

 113:

 114:

 115:

 116:

 117:

 118:

 119:

 120:

 121:

 122:

 123:  //

Configure the options service:

[!code-csharpMain]

   1:  // ASP.NET Core Startup class

2:

   3:  using System;

   4:  using System.Collections.Generic;

   5:  using System.Linq;

   6:  using System.Threading.Tasks;

   7:  using Microsoft.AspNetCore.Builder;

   8:  using Microsoft.AspNetCore.Hosting;

   9:  using Microsoft.Extensions.Configuration;

  10:  using Microsoft.Extensions.DependencyInjection;

  11:  using Microsoft.Extensions.Logging;

  12:  using MyApp.Middleware;

13:

  14:  namespace Asp.Net.Core

  15:  {

  16:      public class Startup

  17:      {

  18:          #region snippet_Ctor

  19:          public Startup(IHostingEnvironment env)

  20:          {

  21:              var builder = new ConfigurationBuilder()

  22:                  .SetBasePath(env.ContentRootPath)

  23:                  .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

  24:                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

  25:                  .AddEnvironmentVariables();

  26:              Configuration = builder.Build();

  27:          }

  28:          #endregion

29:

  30:          public IConfigurationRoot Configuration { get; }

31:

  32:          // This method gets called by the runtime. Use this method to add services to the container.

  33:          #region snippet_ConfigureServices

  34:          public void ConfigureServices(IServiceCollection services)

  35:          {

  36:              // Setup options service

  37:              services.AddOptions();

38:

  39:              // Load options from section "MyMiddlewareOptionsSection"

  40:              services.Configure<MyMiddlewareOptions>(

  41:                  Configuration.GetSection("MyMiddlewareOptionsSection"));

42:

  43:              // Add framework services.

  44:              services.AddMvc();

  45:          }

  46:          #endregion

47:

  48:          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

  49:          #region snippet_Configure

  50:          public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

  51:          {

  52:              loggerFactory.AddConsole(Configuration.GetSection("Logging"));

  53:              loggerFactory.AddDebug();

54:

  55:              if (env.IsDevelopment())

  56:              {

  57:                  app.UseDeveloperExceptionPage();

  58:                  app.UseBrowserLink();

  59:              }

  60:              else

  61:              {

  62:                  app.UseExceptionHandler("/Home/Error");

  63:              }

64:

  65:              app.UseMyMiddleware();

66:

  67:              app.UseMyMiddlewareWithParams();

68:

  69:              var myMiddlewareOptions = Configuration.GetSection("MyMiddlewareOptionsSection").Get<MyMiddlewareOptions>();

  70:              var myMiddlewareOptions2 = Configuration.GetSection("MyMiddlewareOptionsSection2").Get<MyMiddlewareOptions>();

  71:              app.UseMyMiddlewareWithParams(myMiddlewareOptions);

  72:              app.UseMyMiddlewareWithParams(myMiddlewareOptions2);

73:

  74:              app.UseMyTerminatingMiddleware();

75:

  76:              // Create branch to the MyHandlerMiddleware.

  77:              // All requests ending in .report will follow this branch.

  78:              app.MapWhen(

  79:                  context => context.Request.Path.ToString().EndsWith(".report"),

  80:                  appBranch => {

  81:                      // ... optionally add more middleware to this branch

  82:                      appBranch.UseMyHandler();

  83:                  });

84:

  85:              app.MapWhen(

  86:                  context => context.Request.Path.ToString().EndsWith(".context"),

  87:                  appBranch => {

  88:                      appBranch.UseHttpContextDemoMiddleware();

  89:                  });

90:

  91:              app.UseStaticFiles();

92:

  93:              app.UseMvc(routes =>

  94:              {

  95:                  routes.MapRoute(

  96:                      name: "default",

  97:                      template: "{controller=Home}/{action=Index}/{id?}");

  98:              });

  99:          }

 100:          #endregion

 101:      }

 102:  }

 103:

 104:

 105:

 106:

 107:

 108:

 109:

 110:

 111:

 112:

 113:

 114:

 115:

 116:

 117:

 118:

 119:

 120:

 121:

 122:

 123:  //

Associate your options with your options class:

[!code-csharpMain]

   1:  // ASP.NET Core Startup class

2:

   3:  using System;

   4:  using System.Collections.Generic;

   5:  using System.Linq;

   6:  using System.Threading.Tasks;

   7:  using Microsoft.AspNetCore.Builder;

   8:  using Microsoft.AspNetCore.Hosting;

   9:  using Microsoft.Extensions.Configuration;

  10:  using Microsoft.Extensions.DependencyInjection;

  11:  using Microsoft.Extensions.Logging;

  12:  using MyApp.Middleware;

13:

  14:  namespace Asp.Net.Core

  15:  {

  16:      public class Startup

  17:      {

  18:          #region snippet_Ctor

  19:          public Startup(IHostingEnvironment env)

  20:          {

  21:              var builder = new ConfigurationBuilder()

  22:                  .SetBasePath(env.ContentRootPath)

  23:                  .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

  24:                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

  25:                  .AddEnvironmentVariables();

  26:              Configuration = builder.Build();

  27:          }

  28:          #endregion

29:

  30:          public IConfigurationRoot Configuration { get; }

31:

  32:          // This method gets called by the runtime. Use this method to add services to the container.

  33:          #region snippet_ConfigureServices

  34:          public void ConfigureServices(IServiceCollection services)

  35:          {

  36:              // Setup options service

  37:              services.AddOptions();

38:

  39:              // Load options from section "MyMiddlewareOptionsSection"

  40:              services.Configure<MyMiddlewareOptions>(

  41:                  Configuration.GetSection("MyMiddlewareOptionsSection"));

42:

  43:              // Add framework services.

  44:              services.AddMvc();

  45:          }

  46:          #endregion

47:

  48:          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

  49:          #region snippet_Configure

  50:          public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

  51:          {

  52:              loggerFactory.AddConsole(Configuration.GetSection("Logging"));

  53:              loggerFactory.AddDebug();

54:

  55:              if (env.IsDevelopment())

  56:              {

  57:                  app.UseDeveloperExceptionPage();

  58:                  app.UseBrowserLink();

  59:              }

  60:              else

  61:              {

  62:                  app.UseExceptionHandler("/Home/Error");

  63:              }

64:

  65:              app.UseMyMiddleware();

66:

  67:              app.UseMyMiddlewareWithParams();

68:

  69:              var myMiddlewareOptions = Configuration.GetSection("MyMiddlewareOptionsSection").Get<MyMiddlewareOptions>();

  70:              var myMiddlewareOptions2 = Configuration.GetSection("MyMiddlewareOptionsSection2").Get<MyMiddlewareOptions>();

  71:              app.UseMyMiddlewareWithParams(myMiddlewareOptions);

  72:              app.UseMyMiddlewareWithParams(myMiddlewareOptions2);

73:

  74:              app.UseMyTerminatingMiddleware();

75:

  76:              // Create branch to the MyHandlerMiddleware.

  77:              // All requests ending in .report will follow this branch.

  78:              app.MapWhen(

  79:                  context => context.Request.Path.ToString().EndsWith(".report"),

  80:                  appBranch => {

  81:                      // ... optionally add more middleware to this branch

  82:                      appBranch.UseMyHandler();

  83:                  });

84:

  85:              app.MapWhen(

  86:                  context => context.Request.Path.ToString().EndsWith(".context"),

  87:                  appBranch => {

  88:                      appBranch.UseHttpContextDemoMiddleware();

  89:                  });

90:

  91:              app.UseStaticFiles();

92:

  93:              app.UseMvc(routes =>

  94:              {

  95:                  routes.MapRoute(

  96:                      name: "default",

  97:                      template: "{controller=Home}/{action=Index}/{id?}");

  98:              });

  99:          }

 100:          #endregion

 101:      }

 102:  }

 103:

 104:

 105:

 106:

 107:

 108:

 109:

 110:

 111:

 112:

 113:

 114:

 115:

 116:

 117:

 118:

 119:

 120:

 121:

 122:

 123:  //

Inject the options into your middleware constructor. This is similar to injecting options into a controller.

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using Microsoft.Extensions.Options;

   4:  using System.Threading.Tasks;

5:

   6:  namespace MyApp.Middleware

   7:  {

   8:      #region snippet_Options

   9:      public class MyMiddlewareOptions

  10:      {

  11:          public string Param1 { get; set; }

  12:          public string Param2 { get; set; }

  13:      }

  14:      #endregion

15:

  16:      #region snippet_MiddlewareWithParams

  17:      public class MyMiddlewareWithParams

  18:      {

  19:          private readonly RequestDelegate _next;

  20:          private readonly MyMiddlewareOptions _myMiddlewareOptions;

21:

  22:          public MyMiddlewareWithParams(RequestDelegate next,

  23:              IOptions<MyMiddlewareOptions> optionsAccessor)

  24:          {

  25:              _next = next;

  26:              _myMiddlewareOptions = optionsAccessor.Value;

  27:          }

28:

  29:          public async Task Invoke(HttpContext context)

  30:          {

  31:              // Do something with context near the beginning of request processing

  32:              // using configuration in _myMiddlewareOptions

33:

  34:              await _next.Invoke(context);

35:

  36:              // Do something with context near the end of request processing

  37:              // using configuration in _myMiddlewareOptions

  38:          }

  39:      }

  40:      #endregion

41:

  42:      #region snippet_Extensions

  43:      public static class MyMiddlewareWithParamsExtensions

  44:      {

  45:          public static IApplicationBuilder UseMyMiddlewareWithParams(

  46:              this IApplicationBuilder builder)

  47:          {

  48:              return builder.UseMiddleware<MyMiddlewareWithParams>();

  49:          }

50:

  51:          public static IApplicationBuilder UseMyMiddlewareWithParams(

  52:              this IApplicationBuilder builder, MyMiddlewareOptions myMiddlewareOptions)

  53:          {

  54:              return builder.UseMiddleware<MyMiddlewareWithParams>(

  55:                  new OptionsWrapper<MyMiddlewareOptions>(myMiddlewareOptions));

  56:          }

  57:      }

  58:      #endregion

  59:  }

The UseMiddleware extension method that adds your middleware to the IApplicationBuilder takes care of dependency injection.

This is not limited to IOptions objects. Any other object that your middleware requires can be injected this way.

Loading middleware options through direct injection

The options pattern has the advantage that it creates loose coupling between options values and their consumers. Once you’ve associated an options class with the actual options values, any other class can get access to the options through the dependency injection framework. There is no need to pass around options values.

This breaks down though if you want to use the same middleware twice, with different options. For example an authorization middleware used in different branches allowing different roles. You can’t associate two different options objects with the one options class.

The solution is to get the options objects with the actual options values in your Startup class and pass those directly to each instance of your middleware.

Add a second key to appsettings.json

To add a second set of options to the appsettings.json file, use a new key to uniquely identify it:

[!code-jsonMain]

   1:  {

   2:    "Logging": {

   3:      "IncludeScopes": false,

   4:      "LogLevel": {

   5:        "Default": "Debug",

   6:        "System": "Information",

   7:        "Microsoft": "Information"

   8:      }

   9:    },

  10:    "MyMiddlewareOptionsSection2": {

  11:      "Param1": "Param1Value2",

  12:      "Param2": "Param2Value2"

  13:    },

  14:    "MyMiddlewareOptionsSection": {

  15:      "Param1": "Param1Value",

  16:      "Param2": "Param2Value"

  17:    }

  18:  }

Retrieve options values and pass them to middleware. The Use... extension method (which adds your middleware to the pipeline) is a logical place to pass in the option values:

[!code-csharpMain]

   1:  // ASP.NET Core Startup class

2:

   3:  using System;

   4:  using System.Collections.Generic;

   5:  using System.Linq;

   6:  using System.Threading.Tasks;

   7:  using Microsoft.AspNetCore.Builder;

   8:  using Microsoft.AspNetCore.Hosting;

   9:  using Microsoft.Extensions.Configuration;

  10:  using Microsoft.Extensions.DependencyInjection;

  11:  using Microsoft.Extensions.Logging;

  12:  using MyApp.Middleware;

13:

  14:  namespace Asp.Net.Core

  15:  {

  16:      public class Startup

  17:      {

  18:          #region snippet_Ctor

  19:          public Startup(IHostingEnvironment env)

  20:          {

  21:              var builder = new ConfigurationBuilder()

  22:                  .SetBasePath(env.ContentRootPath)

  23:                  .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

  24:                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

  25:                  .AddEnvironmentVariables();

  26:              Configuration = builder.Build();

  27:          }

  28:          #endregion

29:

  30:          public IConfigurationRoot Configuration { get; }

31:

  32:          // This method gets called by the runtime. Use this method to add services to the container.

  33:          #region snippet_ConfigureServices

  34:          public void ConfigureServices(IServiceCollection services)

  35:          {

  36:              // Setup options service

  37:              services.AddOptions();

38:

  39:              // Load options from section "MyMiddlewareOptionsSection"

  40:              services.Configure<MyMiddlewareOptions>(

  41:                  Configuration.GetSection("MyMiddlewareOptionsSection"));

42:

  43:              // Add framework services.

  44:              services.AddMvc();

  45:          }

  46:          #endregion

47:

  48:          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

  49:          #region snippet_Configure

  50:          public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

  51:          {

  52:              loggerFactory.AddConsole(Configuration.GetSection("Logging"));

  53:              loggerFactory.AddDebug();

54:

  55:              if (env.IsDevelopment())

  56:              {

  57:                  app.UseDeveloperExceptionPage();

  58:                  app.UseBrowserLink();

  59:              }

  60:              else

  61:              {

  62:                  app.UseExceptionHandler("/Home/Error");

  63:              }

64:

  65:              app.UseMyMiddleware();

66:

  67:              app.UseMyMiddlewareWithParams();

68:

  69:              var myMiddlewareOptions = Configuration.GetSection("MyMiddlewareOptionsSection").Get<MyMiddlewareOptions>();

  70:              var myMiddlewareOptions2 = Configuration.GetSection("MyMiddlewareOptionsSection2").Get<MyMiddlewareOptions>();

  71:              app.UseMyMiddlewareWithParams(myMiddlewareOptions);

  72:              app.UseMyMiddlewareWithParams(myMiddlewareOptions2);

73:

  74:              app.UseMyTerminatingMiddleware();

75:

  76:              // Create branch to the MyHandlerMiddleware.

  77:              // All requests ending in .report will follow this branch.

  78:              app.MapWhen(

  79:                  context => context.Request.Path.ToString().EndsWith(".report"),

  80:                  appBranch => {

  81:                      // ... optionally add more middleware to this branch

  82:                      appBranch.UseMyHandler();

  83:                  });

84:

  85:              app.MapWhen(

  86:                  context => context.Request.Path.ToString().EndsWith(".context"),

  87:                  appBranch => {

  88:                      appBranch.UseHttpContextDemoMiddleware();

  89:                  });

90:

  91:              app.UseStaticFiles();

92:

  93:              app.UseMvc(routes =>

  94:              {

  95:                  routes.MapRoute(

  96:                      name: "default",

  97:                      template: "{controller=Home}/{action=Index}/{id?}");

  98:              });

  99:          }

 100:          #endregion

 101:      }

 102:  }

 103:

 104:

 105:

 106:

 107:

 108:

 109:

 110:

 111:

 112:

 113:

 114:

 115:

 116:

 117:

 118:

 119:

 120:

 121:

 122:

 123:  //

Enable middleware to take an options parameter. Provide an overload of the Use... extension method (that takes the options parameter and passes it to UseMiddleware). When UseMiddleware is called with parameters, it passes the parameters to your middleware constructor when it instantiates the middleware object.

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using Microsoft.Extensions.Options;

   4:  using System.Threading.Tasks;

5:

   6:  namespace MyApp.Middleware

   7:  {

   8:      #region snippet_Options

   9:      public class MyMiddlewareOptions

  10:      {

  11:          public string Param1 { get; set; }

  12:          public string Param2 { get; set; }

  13:      }

  14:      #endregion

15:

  16:      #region snippet_MiddlewareWithParams

  17:      public class MyMiddlewareWithParams

  18:      {

  19:          private readonly RequestDelegate _next;

  20:          private readonly MyMiddlewareOptions _myMiddlewareOptions;

21:

  22:          public MyMiddlewareWithParams(RequestDelegate next,

  23:              IOptions<MyMiddlewareOptions> optionsAccessor)

  24:          {

  25:              _next = next;

  26:              _myMiddlewareOptions = optionsAccessor.Value;

  27:          }

28:

  29:          public async Task Invoke(HttpContext context)

  30:          {

  31:              // Do something with context near the beginning of request processing

  32:              // using configuration in _myMiddlewareOptions

33:

  34:              await _next.Invoke(context);

35:

  36:              // Do something with context near the end of request processing

  37:              // using configuration in _myMiddlewareOptions

  38:          }

  39:      }

  40:      #endregion

41:

  42:      #region snippet_Extensions

  43:      public static class MyMiddlewareWithParamsExtensions

  44:      {

  45:          public static IApplicationBuilder UseMyMiddlewareWithParams(

  46:              this IApplicationBuilder builder)

  47:          {

  48:              return builder.UseMiddleware<MyMiddlewareWithParams>();

  49:          }

50:

  51:          public static IApplicationBuilder UseMyMiddlewareWithParams(

  52:              this IApplicationBuilder builder, MyMiddlewareOptions myMiddlewareOptions)

  53:          {

  54:              return builder.UseMiddleware<MyMiddlewareWithParams>(

  55:                  new OptionsWrapper<MyMiddlewareOptions>(myMiddlewareOptions));

  56:          }

  57:      }

  58:      #endregion

  59:  }

Note how this wraps the options object in an OptionsWrapper object. This implements IOptions, as expected by the middleware constructor.

Migrating to the new HttpContext

You saw earlier that the Invoke method in your middleware takes a parameter of type HttpContext:

public async Task Invoke(HttpContext context)

HttpContext has significantly changed in ASP.NET Core. This section shows how to translate the most commonly used properties of System.Web.HttpContext to the new Microsoft.AspNetCore.Http.HttpContext.

HttpContext

HttpContext.Items translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

Unique request ID (no System.Web.HttpContext counterpart)

Gives you a unique id for each request. Very useful to include in your logs.

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request

HttpContext.Request.HttpMethod translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.QueryString translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.Url and HttpContext.Request.RawUrl translate to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.IsSecureConnection translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.UserHostAddress translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.Cookies translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.RequestContext.RouteData translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.Headers translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.UserAgent translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.UrlReferrer translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.ContentType translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Request.Form translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

[!WARNING] Read form values only if the content sub type is x-www-form-urlencoded or form-data.

HttpContext.Request.InputStream translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

[!WARNING] Use this code only in a handler type middleware, at the end of a pipeline.

You can read the raw body as shown above only once per request. Middleware trying to read the body after the first read will read an empty body.

This does not apply to reading a form as shown earlier, because that is done from a buffer.

HttpContext.Response

HttpContext.Response.Status and HttpContext.Response.StatusDescription translate to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType translate to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Response.ContentType on its own also translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Response.Output translates to:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Response.TransmitFile

Serving up a file is discussed here.

HttpContext.Response.Headers

Sending response headers is complicated by the fact that if you set them after anything has been written to the response body, they will not be sent.

The solution is to set a callback method that will be called right before writing to the response starts. This is best done at the start of the Invoke method in your middleware. It is this callback method that sets your response headers.

The following code sets a callback method called SetHeaders:

public async Task Invoke(HttpContext httpContext)
{
    // ...
    httpContext.Response.OnStarting(SetHeaders, state: httpContext);

The SetHeaders callback method would look like this:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

HttpContext.Response.Cookies

Cookies travel to the browser in a Set-Cookie response header. As a result, sending cookies requires the same callback as used for sending response headers:

public async Task Invoke(HttpContext httpContext)
{
    // ...
    httpContext.Response.OnStarting(SetCookies, state: httpContext);
    httpContext.Response.OnStarting(SetHeaders, state: httpContext);

The SetCookies callback method would look like the following:

[!code-csharpMain]

   1:  using Microsoft.AspNetCore.Builder;

   2:  using Microsoft.AspNetCore.Http;

   3:  using System.Collections.Generic;

   4:  using System.Threading.Tasks;

   5:  using Microsoft.Net.Http.Headers;

   6:  using Microsoft.AspNetCore.Http.Extensions;

   7:  using Microsoft.AspNetCore.Routing;

8:

   9:  namespace MyApp.Middleware

  10:  {

  11:      public class HttpContextDemoMiddleware

  12:      {

  13:          private readonly RequestDelegate _next;

14:

  15:          public HttpContextDemoMiddleware(RequestDelegate next)

  16:          {

  17:              _next = next;

  18:          }

19:

  20:          public async Task Invoke(HttpContext httpContext)

  21:          {

  22:              // OnStarting handlers have to be set early during request processing,

  23:              // even though they are used to create the response.

24:

  25:              // ----------------------

  26:              // ASP.NET 4 - HttpContext.Response.Headers

  27:              // ASP.NET 4 - HttpContext.Response.Cookies

  28:              //

  29:              // Issue with all response headers is that they will not be sent

  30:              // after anything has been written to the response body.

  31:              // To solve this, use OnStarting to set a callback that will be called

  32:              // right before headers are sent. Set the headers in that callback.

  33:              //

  34:              // Setting a cookie results in a Set-Cookie response header.

  35:              // So use an OnStarting handler here as well.

36:

  37:              //>40

  38:              httpContext.Response.OnStarting(SetHeaders, state: httpContext);

  39:              httpContext.Response.OnStarting(SetCookies, state: httpContext);

  40:              //<40

41:

  42:              // ==================================================================

  43:              // Context

44:

  45:              // Unique request ID (no ASP.NET 4 counterpart)

  46:              #region snippet_Trace

  47:              string requestId = httpContext.TraceIdentifier;

  48:              #endregion

49:

  50:              // ASP.NET 4 - HttpContext.Items

  51:              #region snippet_Items

  52:              IDictionary<object, object> items = httpContext.Items;

  53:              #endregion

54:

  55:              // ==================================================================

  56:              // Request

57:

  58:              // ASP.NET 4 - HttpContext.Request.HttpMethod

  59:              #region snippet_Method

  60:              string httpMethod = httpContext.Request.Method;

  61:              #endregion

62:

  63:              // ----------

64:

  65:              // ASP.NET 4 - HttpContext.Request.QueryString

  66:              #region snippet_Query

  67:              IQueryCollection queryParameters = httpContext.Request.Query;

68:

  69:              // If no query parameter "key" used, values will have 0 items

  70:              // If single value used for a key (...?key=v1), values will have 1 item ("v1")

  71:              // If key has multiple values (...?key=v1&key=v2), values will have 2 items ("v1" and "v2")

  72:              IList<string> values = queryParameters["key"];

73:

  74:              // If no query parameter "key" used, value will be ""

  75:              // If single value used for a key (...?key=v1), value will be "v1"

  76:              // If key has multiple values (...?key=v1&key=v2), value will be "v1,v2"

  77:              string value = queryParameters["key"].ToString();

  78:              #endregion

79:

  80:              // ASP.NET 4 - HttpContext.Request.Url and HttpContext.Request.RawUrl

  81:              #region snippet_Url

  82:              // using Microsoft.AspNetCore.Http.Extensions;

  83:              var url = httpContext.Request.GetDisplayUrl();

  84:              #endregion

85:

  86:              // ASP.NET 4 - HttpContext.Request.IsSecureConnection

  87:              #region snippet_Secure

  88:              var isSecureConnection = httpContext.Request.IsHttps;

  89:              #endregion

90:

  91:              // ASP.NET 4 - HttpContext.Request.UserHostAddress

  92:              #region snippet_Host

  93:              var userHostAddress = httpContext.Connection.RemoteIpAddress?.ToString();

  94:              #endregion

95:

  96:              // ASP.NET 4 - HttpContext.Request.Cookies

  97:              #region snippet_Cookies

  98:              IRequestCookieCollection cookies = httpContext.Request.Cookies;

  99:              string unknownCookieValue = cookies["unknownCookie"]; // will be null (no exception)

 100:              string knownCookieValue = cookies["cookie1name"];     // will be actual value

 101:              #endregion

 102:

 103:              // ASP.NET 4 - HttpContext.Request.RequestContext.RouteData

 104:              // using Microsoft.AspNetCore.Routing;

 105:              #region snippet_Route

 106:              var routeValue = httpContext.GetRouteValue("key");

 107:              #endregion

 108:

 109:              // ASP.NET 4 - HttpContext.Request.Headers

 110:              #region snippet_Headers

 111:              // using Microsoft.AspNetCore.Http.Headers;

 112:              // using Microsoft.Net.Http.Headers;

 113:

 114:              IHeaderDictionary headersDictionary = httpContext.Request.Headers;

 115:

 116:              // GetTypedHeaders extension method provides strongly typed access to many headers

 117:              var requestHeaders = httpContext.Request.GetTypedHeaders();

 118:              CacheControlHeaderValue cacheControlHeaderValue = requestHeaders.CacheControl;

 119:

 120:              // For unknown header, unknownheaderValues has zero items and unknownheaderValue is ""

 121:              IList<string> unknownheaderValues = headersDictionary["unknownheader"];

 122:              string unknownheaderValue = headersDictionary["unknownheader"].ToString();

 123:

 124:              // For known header, knownheaderValues has 1 item and knownheaderValue is the value

 125:              IList<string> knownheaderValues = headersDictionary[HeaderNames.AcceptLanguage];

 126:              string knownheaderValue = headersDictionary[HeaderNames.AcceptLanguage].ToString();

 127:              #endregion

 128:

 129:              // ASP.NET 4 - HttpContext.Request.UserAgent

 130:              #region snippet_Agent

 131:              string userAgent = headersDictionary[HeaderNames.UserAgent].ToString();

 132:              #endregion

 133:

 134:              // ASP.NET 4 - HttpContext.Request.UrlReferrer

 135:              #region snippet_Referrer

 136:              string urlReferrer = headersDictionary[HeaderNames.Referer].ToString();

 137:              #endregion

 138:

 139:              // ASP.NET 4 - HttpContext.Request.ContentType

 140:              #region snippet_Type

 141:              // using Microsoft.Net.Http.Headers;

 142:

 143:              MediaTypeHeaderValue mediaHeaderValue = requestHeaders.ContentType;

 144:              string contentType = mediaHeaderValue?.MediaType;   // ex. application/x-www-form-urlencoded

 145:              string contentMainType = mediaHeaderValue?.Type;    // ex. application

 146:              string contentSubType = mediaHeaderValue?.SubType;  // ex. x-www-form-urlencoded

 147:

 148:              System.Text.Encoding requestEncoding = mediaHeaderValue?.Encoding;

 149:              #endregion

 150:

 151:              // ASP.NET 4 - HttpContext.Request.Form

 152:              #region snippet_Form

 153:              if (httpContext.Request.HasFormContentType)

 154:              {

 155:                  IFormCollection form;

 156:

 157:                  form = httpContext.Request.Form; // sync

 158:                  // Or

 159:                  form = await httpContext.Request.ReadFormAsync(); // async

 160:

 161:                  string firstName = form["firstname"];

 162:                  string lastName = form["lastname"];

 163:              }

 164:              #endregion

 165:

 166:              // ----------

 167:              // See

 168:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 169:

 170:              // ASP.NET 4 - HttpContext.Request.InputStream

 171:              // Unlike reading the form, reading the raw body is not from a buffer.

 172:              // So you can only do this once per request.

 173:              //

 174:              // If you need to read the body multiple times per request, see

 175:              // http://stackoverflow.com/questions/31389781/read-body-twice-in-asp-net-5/

 176:

 177:              #region snippet_Input

 178:              string inputBody;

 179:              using (var reader = new System.IO.StreamReader(

 180:                  httpContext.Request.Body, System.Text.Encoding.UTF8))

 181:              {

 182:                  inputBody = reader.ReadToEnd();

 183:              }

 184:              #endregion

 185:

 186:              // Use this middleware as a handler, so no call to

 187:              // await _next.Invoke(aspnetCoreHttpContext);

 188:

 189:              // ==================================================================

 190:              // Response

 191:

 192:              // ASP.NET 4 - HttpContext.Response.Status

 193:              // ASP.NET 4 - HttpContext.Response.StatusDescription (obsolete, removed from HTTP/2)

 194:              #region snippet_Status

 195:              // using Microsoft.AspNetCore.Http;

 196:              httpContext.Response.StatusCode = StatusCodes.Status200OK;

 197:              #endregion

 198:

 199:              // ASP.NET 4 - HttpContext.Response.ContentEncoding and HttpContext.Response.ContentType

 200:              #region snippet_RespType

 201:              // using Microsoft.Net.Http.Headers;

 202:              var mediaType = new MediaTypeHeaderValue("application/json");

 203:              mediaType.Encoding = System.Text.Encoding.UTF8;

 204:              httpContext.Response.ContentType = mediaType.ToString();

 205:              #endregion

 206:

 207:              // ASP.NET 4 - HttpContext.Response.ContentType only

 208:              #region snippet_RespTypeOnly

 209:              httpContext.Response.ContentType = "text/html";

 210:              #endregion

 211:

 212:              // ASP.NET 4 - HttpContext.Response.Output

 213:              #region  snippet_Output

 214:              string responseContent = GetResponseContent();

 215:              await httpContext.Response.WriteAsync(responseContent);

 216:              #endregion

 217:          }

 218:

 219:          #region snippet_SetHeaders

 220:          // using Microsoft.AspNet.Http.Headers;

 221:          // using Microsoft.Net.Http.Headers;

 222:

 223:          private Task SetHeaders(object context)

 224:          {

 225:              var httpContext = (HttpContext)context;

 226:

 227:              // Set header with single value

 228:              httpContext.Response.Headers["ResponseHeaderName"] = "headerValue";

 229:

 230:              // Set header with multiple values

 231:              string[] responseHeaderValues = new string[] { "headerValue1", "headerValue1" };

 232:              httpContext.Response.Headers["ResponseHeaderName"] = responseHeaderValues;

 233:

 234:              // Translating ASP.NET 4's HttpContext.Response.RedirectLocation

 235:              httpContext.Response.Headers[HeaderNames.Location] = "http://www.example.com";

 236:              // Or

 237:              httpContext.Response.Redirect("http://www.example.com");

 238:

 239:              // GetTypedHeaders extension method provides strongly typed access to many headers

 240:              var responseHeaders = httpContext.Response.GetTypedHeaders();

 241:

 242:              // Translating ASP.NET 4's HttpContext.Response.CacheControl

 243:              responseHeaders.CacheControl = new CacheControlHeaderValue

 244:              {

 245:                  MaxAge = new System.TimeSpan(365, 0, 0, 0)

 246:                  // Many more properties available

 247:              };

 248:

 249:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 250:              return Task.FromResult(0);

 251:          }

 252:          #endregion

 253:

 254:          #region snippet_SetCookies

 255:          private Task SetCookies(object context)

 256:          {

 257:              var httpContext = (HttpContext)context;

 258:

 259:              IResponseCookies responseCookies = httpContext.Response.Cookies;

 260:

 261:              responseCookies.Append("cookie1name", "cookie1value");

 262:              responseCookies.Append("cookie2name", "cookie2value",

 263:                  new CookieOptions { Expires = System.DateTime.Now.AddDays(5), HttpOnly = true });

 264:

 265:              // If you use .Net 4.6+, Task.CompletedTask will be a bit faster

 266:              return Task.FromResult(0);

 267:          }

 268:          #endregion

 269:

 270:          // You would normally use MVC to generate HTML like this.

 271:          private string GetResponseContent()

 272:          {

 273:              return @"

 274:  <!DOCTYPE html>

 275:  <html lang=""en"">

 276:  <head>

 277:      <title>index</title>

 278:  </head>

 279:  <body>

 280:  <form action=""form.context"" method=""post"">

 281:      <input type=""text"" name=""firstname"">

 282:      <input type=""text"" name=""lastname"">

 283:      <input type=""submit"" value=""Submit"">

 284:  </form>

 285:  </body>

 286:  </html>

 287:  ";

 288:          }

 289:      }

 290:

 291:      public static class HttpContextDemoMiddlewareExtensions

 292:      {

 293:          public static IApplicationBuilder UseHttpContextDemoMiddleware(this IApplicationBuilder builder)

 294:          {

 295:              return builder.UseMiddleware<HttpContextDemoMiddleware>();

 296:          }

 297:      }

 298:  }

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