asp.net – 用于集成的IIS 7的自定义HttpModule

这是我的web.config部分：

<system.webServer>
  <modules>
    <add name="AspExceptionHandler" 
         type="Company.Exceptions.AspExceptionHandler,Company.Exceptions" 
         preCondition="managedHandler" />
  </modules>
</system.webServer>

这是我的HttpModule中的代码：

using System;
using System.Web;
using Company.Settings;
using System.Configuration;

namespace Company.Exceptions
{
  public class AspExceptionHandler : IHttpModule
  {
    public void Dispose() { }

    public void Init(HttpApplication application)
    {
      application.Error += new EventHandler(ErrorHandler);
    }

    private void ErrorHandler(object sender,EventArgs e)
    {
      HttpApplication application = (HttpApplication)sender;
      HttpContext currentContext = application.Context;

      // Gather information5
      Exception currentException = application.Server.GetLastError();
      String errorPage = "http://www.mycompaniesmainsite.com/error.html";

      HttpException httpException = currentException as HttpException;
      if (httpException == null || httpException.GetHttpCode() != 404)
      {          
        currentContext.Server.Transfer(errorPage,true);
      }
      else
      {
        application.Response.Status = "404 Not Found";
        application.Response.StatusCode = 404;
        application.Response.StatusDescription = "Not Found";
        currentContext.Server.Transfer(errorPage,true);
      }
    }
  }
}

有人可以向我解释我的错误,以及IIS 7集成管理管道模式的工作原理吗？因为我发现的大部分答案都是为IIS 6配置HttpModule.