ASP.NET Core中间件计算Http请求时间示例详解_ASP.NET教程

ASP.NET Core中间件计算Http请求时间示例详解

2020-06-16 12:23Rohmeng ASP.NET教程

这篇文章主要给大家介绍了关于ASP.NET Core中间件计算Http请求时间的相关资料，文中通过示例代码介绍的非常详细，对大家学习或者使用ASP.NET Core具有一定的参考学习价值，需要的朋友们下面来一起学习学习吧

ASP.NET Core通过RequestDelegate这个委托类型来定义中间件

				?

									public delegate Task RequestDelegate(HttpContext context);

可将一个单独的请求委托并行指定为匿名方法（称为并行中间件），或在类中对其进行定义。可通过Use，或在Middleware类中配置要传递给委托执行的方法(参数类型HttpContext，返回值类型Task)。

				?

									public static IApplicationBuilder Use(this IApplicationBuilder app, Func<HttpContext, Func<Task>, Task> middleware);

									public static IApplicationBuilder UseMiddleware<TMiddleware>(this IApplicationBuilder app, params object[] args);

通过定义一个中间件类来计算http请求的时间，例：

				?

									public class ResponseTimeMiddleware

									{

									  // Name of the Response Header, Custom Headers starts with "X-" 

									  private const string RESPONSE_HEADER_RESPONSE_TIME = "X-Response-Time-ms";

									  // Handle to the next Middleware in the pipeline 

									  private readonly RequestDelegate _next;

									  public ResponseTimeMiddleware(RequestDelegate next)

									  {

									    _next = next;

									  }

									  public Task InvokeAsync(HttpContext context)

									  {

									    // Start the Timer using Stopwatch 

									    var watch = new Stopwatch();

									    watch.Start();

									    context.Response.OnStarting(() => {

									      // Stop the timer information and calculate the time  

									      watch.Stop();

									      var responseTimeForCompleteRequest = watch.ElapsedMilliseconds;

									      // Add the Response time information in the Response headers.  

									      context.Response.Headers[RESPONSE_HEADER_RESPONSE_TIME] = responseTimeForCompleteRequest.ToString();

									      return Task.CompletedTask;

									    });

									    // Call the next delegate/middleware in the pipeline  

									    return this._next(context);

									  }

									}