.netcore2.1 记录http请求时间

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);
  }
}

using Microsoft.AspNetCore.Builder;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace MyApi.Middleware
{
    public static class MyMiddlewareExtensions
    {
        public static IApplicationBuilder UseMyMiddleware(this IApplicationBuilder builder)
        {
            return builder.UseMiddleware();
        }
    }
}

     public void Configure(IApplicationBuilder app, IHostingEnvironment env,
            Microsoft.AspNetCore.Hosting.IApplicationLifetime lifetime)
        {
        
            //跨域设置
            app.UseCors(builder => builder
                .AllowAnyOrigin()
                .AllowAnyMethod()
                .AllowAnyHeader()
                .AllowCredentials());
            app.UseHttpsRedirection();

            app.UseMyMiddleware();//注册中间件

            app.UseMvc();

       

        }