如何通过OWIN实现global.asax事件

Question

从asp.net 6开始,没有名为global.asax的文件,但global.asax有很多类似的事件

·Application_Init

·Application_Start

·Session_Start

·Application_BeginRequest

·Application_EndRequest

·Application_AuthenticateRequest

· 应用程序错误

·Session_End

·Application_End

例如,我经常使用Application_BeginRequest事件来重定向用户.这是一个示例代码

protected void Application_BeginRequest(Object sender, EventArgs e)
{
            if (HttpContext.Current.Request.Url.ToString().ToLower().Contains("content.aspx?content=gm-mdi-diagnostic-tool"))
            {
                Response.RedirectPermanent("http://shop.bba-reman.com/product-category/diagnostic-tools/oem-diagnostic-tools/", true);
            }
            else if (HttpContext.Current.Request.Url.ToString().ToLower().Contains("content.aspx?content=landrover_rover_t4_testbook_lite_diagnostic_tool_ids"))
            {
                Response.RedirectPermanent("http://shop.bba-reman.com/shop/oem-diagnostic-tools/land-rover-t4-mobile/", true);
            }
            else if (HttpContext.Current.Request.Url.ToString().ToLower().Contains("content.aspx?content=ford_ids_main_dealer_tool_mazda_jaguar_landrover"))
            {
                Response.RedirectPermanent("http://shop.bba-reman.com/product-category/diagnostic-tools/oem-diagnostic-tools/", true);
            }
            else if (HttpContext.Current.Request.Url.ToString().ToLower().Contains("content=coda_fuelling_tester_dynamically_measure_fuel_flow_and_pressure_in_situ_under_load"))
            {
                Response.RedirectPermanent("http://shop.bba-reman.com/product-category/diagnostic-tools/", true);
            }
}            

那么告诉我如何用OWIN做同样的事情？与代码示例讨论.

还告诉我如何捕捉session start / end or application start or end从OWIN class code？

请讨论谢谢

Answer 1

如果您需要在每个请求之前执行一些自定义,我建议您使用标准方法:创建中间件并将其插入HTTP请求管道中.

创建中间件有很多种方法,但为了清晰和可维护性,创建一个新类是一个不错的选择.这是一个例子:

public class MyMiddleware
{
  private readonly RequestDelegate next;

  public MyMiddleware(RequestDelegate next)
  {
    this.next = next;
  }

  public async Task Invoke(HttpContext context)
  {
    this.BeginInvoke(context);
    await this.next.Invoke(context);
    this.EndInvoke(context);
  }

  private void BeginInvoke(HttpContext context)
  {
    // Do custom work before controller execution
  }

  private void EndInvoke(HttpContext context)
  {
    // Do custom work after controller execution
  }
}

接下来,它只是注册中间件.这是在Startup类的Configure方法中完成的:

public class Startup
{
  public void Configure(IApplicationBuilder app)
  {
    ...
    app.UseMiddleware<MyMiddleware>();
    ...
  }
}

就这样.并忘记global.asax ;-)