禁用ASP.NET Web API 2中的* all *异常处理(为我自己腾出空间)? [英] Disable *all* exception handling in ASP.NET Web API 2 (to make room for my own)?

问题描述

我想在中间件组件中连接异常处理，如下所示:

public override async Task Invoke(IOwinContext context)
{
    try
    {
        await Next.Invoke(context);
    }
    catch (Exception ex)
    {
        // Log error and return 500 response
    }
}

但是，我想捕获的一些异常在被Web API管道捕获并转换为HttpErrorResponse之前就可以获取.在此过程中，我丢失了许多有关错误的详细信息，因此在进行调试等操作时，我无法获得有用的堆栈跟踪信息(引发异常时调试器甚至都不会停止-我必须手动浏览代码，看看失败了...).

我尝试通过以下实现添加自定义异常处理程序:

public Task HandleAsync(ExceptionHandlerContext context, CancellationToken cancellationToken)
{
    var owinContext = context.Request.GetOwinContext();
    owinContext.Set(Constants.ContextKeys.Exception, context.Exception);
    return Task.FromResult(0);
}

在我的启动配置中通过config.Services.Replace(typeof(IExceptionHandler), new MyExceptionHandler());注册，但是在通过

context.Get<Exception>(Constants.ContextKeys.Exception);

执行后通过

context.Get<Exception>(Constants.ContextKeys.Exception);

查看

context.Get<Exception>(Constants.ContextKeys.Exception);

still 并没有提供我想要的所有详细信息，也没有提供调试器在故障点停止的信息.

有没有办法完全 关闭所有内置错误处理，以便我自己的中间件可以解决?

澄清，因为很多人似乎误会了我的追求:

• Web API中的内置错误处理功能捕获一些(但不是全部)异常并将其重写为500个响应.
• 我想捕获所有 异常，进行一些日志记录，然后然后用我选择的信息发出500个响应 (对于大多数情况，请参阅下一个项目符号.)
• 还有一些表示业务逻辑故障的异常，我想为其返回40倍的错误.
• 我希望它位于(app)管道的顶部，即在请求生命周期中包装其他其他
• 我想使用OWIN来处理此问题，以使其可移植到将来可能出现的自托管方案(即，并非始终将这个应用程序始终托管在IIS上是一成不变的-HTTP模块，Global.asax.cs等)在这里不相关).

解决方案

更新: 解决方案

Update: I blogged about this. When researching the blog post, I found some potential for improvement; I've updated the relevant parts of this answer. For more detail on why I think this is better than all other suggestions here, or the default behavior, read the entire post :)

---

I have now gone with the following approach, which seems to work OK, even if not 100 % compliant with what I was looking for:

• Create a class PassthroughExceptionHandler:

  public class PassthroughExceptionHandler : IExceptionHandler
  {
      public Task HandleAsync(ExceptionHandlerContext context, CancellationToken cancellationToken)
      {
          // don't just throw the exception; that will ruin the stack trace
          var info = ExceptionDispatchInfo.Capture(context.Exception);
          info.Throw();
          return Task.CompletedTask;
      }
  }
  

• Let that class replace the IExceptionHandler service of Web API:

  config.Services.Replace(typeof(IExceptionHandler), new PassthroughExceptionHandler());
  

• Create a middleware class which does what I want:

  public class ExceptionHandlerMiddleware
  {
      public override async Task Invoke(IOwinContext context)
      {
          try
          {
              await Next?.Invoke(context);
          }
          catch (Exception ex)
          {
              // handle and/or log
          }
      }
  }
  

• Register that middleware first in the stack:

  app.Use<ExceptionHandlerMiddleware>()
     .UseStageMarker(PipelineStage.Authenticate)
     // other middlewares omitted for brevity
     .UseStageMarker(PipelineStage.PreHandlerExecute)
     .UseWebApi(config);
  

I will still award the bounty to anyone who comes up with (bounty expired...) I'm still looking for a better solution, which, for example, breaks when an unhandled exception is thrown. (This approach makes VS break when I rethrow the exception in the handler, but the original call stack is lost; I have to set a breakpoint at the faulting line and debug again to be able to intercept the state when an exception is thrown.)

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