在.net Core 中像以前那样的使用 HttpContext.Current

1.首先我们要创建一个静态类

public static class MyHttpContext
  {     
      public static IServiceProvider ServiceProvider;
      public static Microsoft.AspNetCore.Http.HttpContext Current
      {
          get
          {
              object factory = ServiceProvider.GetService(typeof(Microsoft.AspNetCore.Http.IHttpContextAccessor));
              Microsoft.AspNetCore.Http.HttpContext context = ((Microsoft.AspNetCore.Http.HttpContextAccessor)factory).HttpContext;
              return context;
          }
      }
 
  }

2：　然后在startup.cs文件中

　　在Configure方法 添加

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

3. 改写ConfigureServices方法 2.0写法

public void Configure(IApplicationBuilder app, IHostingEnvironment env,  IServiceProvider svp)
      {
      ///省n多代码
        Models.MyHttpContext.ServiceProvider = svp
} 

3.X以上写法

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
        {
            MyHttpContext.ServiceProvider = app.ApplicationServices;
}

在Configure方法的参数中加IServiceProvider svp；并在方法体中加 Models.MyHttpContext.ServiceProvider = svp; 其中MyHttpContext和声明的静态类名是一样的；

在程序基础类库中使用MyHttpContext