asp.net通过httpModule计算页面的执行时间

using System;
using System.Collections.Generic;
using System.Web;//引用web命名空间
using System.Text;
namespace TimerHttpModule
{
public class Class1:IHttpModule//继承IHttpModules
{
public void Init(HttpApplication application)//实现IHttpModules中的Init事件
{
//订阅两个事件
application.BeginRequest +=new EventHandler(application_BeginRequest);
application.EndRequest+=new EventHandler(application_EndRequest);
}
private DateTime starttime;
private void application_BeginRequest(object sender, EventArgs e)
{
//object sender是BeginRequest传递过来的对象
//里面存储的就是HttpApplication实例
//HttpApplication实例里包含HttpContext属性
starttime = DateTime.Now;
}
private void application_EndRequest(object sender, EventArgs e)
{
DateTime endtime = DateTime.Now;
HttpApplication application = (HttpApplication)sender;
HttpContext cOntext= application.Context;
context.Response.Write("

页面执行时间：" + (endtime - starttime).ToString() + "

");
}
//必须实现dispose接口
public void Dispose() { }
}
}