.net Core中间件实战

   新建一个ASP.NET Core Web Application 项目选中空模板

然后为项目添加一个Microsoft.Extensions.Logging.Console

由于我用的.net core1.1 则选择对应1.1版本

添加好了以后新建一个类RequestIPMiddleware.cs

using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace xzyCore
{ 
  public class RequestIPMiddleware  
  {       
    private readonly RequestDelegate _next;
          
    private readonly ILogger _logger;
         
    public RequestIPMiddleware(RequestDelegate next, ILoggerFactory loggerFactory) {
        _next = next;
        _logger =loggerFactory.CreateLogger<RequestIPMiddleware>();
    }
         
    public async Task Invoke(HttpContext context) {      
        _logger.LogInformation("User IP:" + context.Connection.RemoteIpAddress.ToString());
        await _next.Invoke(context);
    } 
  }
}

　　然后在创建一个RequestIPExtensions.cs

using Microsoft.AspNetCore.Builder;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace xzyCore
{
  public static class RequestIPExtensions  
  {       
    public static IApplicationBuilder UseRequestIP(this IApplicationBuilder builder) {
        return builder.UseMiddleware<RequestIPMiddleware>();      
    } 
  }
}

这样就编写好一个中间件了。

在Startup.cs中添加app.UseRequestIP();

 // This method gets called by the runtime. Use this
method to configure the HTTP request pipeline.   
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)     
{
            loggerFactory.AddConsole();
            app.UseRequestIP();
            if(env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            } 
            app.Run(async (context) =>
            {
               await context.Response.WriteAsync("Hello
World!");
            });
}

然后在运行程序

成功运行，这里我们还可以对这个中间件进行进一步改进，增加更多的功能，如限制访问等。