Net Core中介軟體封裝原理示例demo解析
阿新 • • 發佈:2019-01-28
目的: 建立一個在接收到請求之後,將請求的地址列印在後臺伺服器視窗上的中介軟體
注意: 該專案是通過 vs2017 新建專案-> Net Core -> ASP.NET Web應用程式 -> 空 模板 初始化
- 建立一個 RequestExtensions.cs 的檔案,這個檔案用來擴充套件增加一箇中間件
using Microsoft.AspNetCore.Builder;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace MiddlelewareDemo
{
public static class RequestIpExtensions
{
public static IApplicationBuilder UseRequestIp(this IApplicationBuilder builder)
{
return builder.UseMiddleware<RequestIPMiddleware>();
}
}
}
- 建立一個 RequestIPMiddleware.cs 的檔案,這個檔案是中介軟體的具體實現(獲取遠端訪問的地址,並將該地址輸出到伺服器控制檯上)
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace MiddlelewareDemo
{
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);
}
}
}
- 接下來我們在 Startup.cs 中使用該中介軟體,用 app.UseRequestIp(); 呼叫。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
namespace MiddlelewareDemo
{
public class Startup
{
// This method gets called by the runtime. Use this method to add services to the container.
// For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
public void ConfigureServices(IServiceCollection services)
{
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseDefaultFiles();
app.UseRequestIp();
app.Run(async (context) =>
{
await context.Response.WriteAsync("Hello 0 World!");
});
}
}
}
- Program.cs檔案的程式碼:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
namespace MiddlelewareDemo
{
public class Program
{
public static void Main(string[] args)
{
BuildWebHost(args).Run();
}
public static IWebHost BuildWebHost(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.Build();
}
}
執行效果:
我們看到 中介軟體呼叫成功,在瀏覽器訪問的時候在後臺成功打印出了 IP xxxxx。