问全局记录来自ASP.NET [ScriptService]服务的异常

EN

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Web;

public class ErrorHandlerModule : IHttpModule {

  public void Init(HttpApplication context) {
    context.PostRequestHandlerExecute += OnPostRequestHandlerExecute;
    context.EndRequest += OnEndRequest;
  }

  static void OnPostRequestHandlerExecute(object sender, EventArgs e) {
    HttpApplication context = (HttpApplication) sender;
    // TODO: Update with the correct check for your application
    if (context.Request.Path.StartsWith("/HelloService.asmx") 
        && context.Response.StatusCode == 500) {
      context.Response.Filter = 
        new ErrorHandlerFilter(context.Response.Filter);
      context.EndRequest += OnEndRequest;
    }
  }

  static void OnEndRequest(object sender, EventArgs e) {
    HttpApplication context = (HttpApplication) sender;
    ErrorHandlerFilter errorHandlerFilter = 
      context.Response.Filter as ErrorHandlerFilter;
    if (errorHandlerFilter == null) {
      return;
    }

    string originalContent =
      Encoding.UTF8.GetString(
        errorHandlerFilter.OriginalBytesWritten.ToArray());

    // If customErrors are Off then originalContent will contain JSON with
    // the original exception message, stack trace and exception type.

    // TODO: log the exception
  }

  public void Dispose() { }
}

public class ErrorHandlerFilter : Stream {

  private readonly Stream _responseFilter;

  public List OriginalBytesWritten { get; private set; }

  private const string Content = 
    "{\"Message\":\"There was an error processing the request.\"" +
    ",\"StackTrace\":\"\",\"ExceptionType\":\"\"}";

  public ErrorHandlerFilter(Stream responseFilter) {
    _responseFilter = responseFilter;
    OriginalBytesWritten = new List();
  }

  public override void Flush() {
    byte[] bytes = Encoding.UTF8.GetBytes(Content);
    _responseFilter.Write(bytes, 0, bytes.Length);
    _responseFilter.Flush();
  }

  public override long Seek(long offset, SeekOrigin origin) {
    return _responseFilter.Seek(offset, origin);
  }

  public override void SetLength(long value) {
    _responseFilter.SetLength(value);
  }

  public override int Read(byte[] buffer, int offset, int count) {
    return _responseFilter.Read(buffer, offset, count);
  }

  public override void Write(byte[] buffer, int offset, int count) {
    for (int i = offset; i < offset + count; i++) {
      OriginalBytesWritten.Add(buffer[i]);
    }
  }

  public override bool CanRead {
    get { return _responseFilter.CanRead; }
  }

  public override bool CanSeek {
    get { return _responseFilter.CanSeek; }
  }

  public override bool CanWrite {
    get { return _responseFilter.CanWrite; }
  }

  public override long Length {
    get { return _responseFilter.Length; }
  }

  public override long Position {
    get { return _responseFilter.Position; }
    set { _responseFilter.Position = value; }
  }
}