DateTime   dt;   

protected void Application_Start(object sender, EventArgs e)
{
     dt   =   DateTime.Now;  
}

protected void Application_End(object sender, EventArgs e)
{
    DateTime   dt2   =   DateTime.Now;   
    TimeSpan   ts   =   dt2   -   dt;   
    Response.Write("the   request   takes   "   +   ts.TotalMilliseconds.ToString()   +   "   milliseconds<BR>");   

}

        protected DateTime dt;
        protected void Page_Load(object sender, EventArgs e)
        {
            
        }
        protected override void OnPreInit(EventArgs e)
        {
            dt = DateTime.Now;
            base.OnPreInit(e);
        }

        protected override void OnLoadComplete(EventArgs e)
        {
            base.OnLoadComplete(e);
            TimeSpan ts = DateTime.Now - dt;
            Response.Write("加载页面用时：" + ts.TotalMilliseconds);
        }

        DateTime dt;

        protected void Application_BeginRequest(Object sender, EventArgs E)
        {

            dt = DateTime.Now;
        }

        protected void Application_EndRequest(Object sender, EventArgs E)
        {

            DateTime dt2 = DateTime.Now;
            TimeSpan ts = dt2 - dt;
            Response.Write("The request takes " + ts.TotalMilliseconds.ToString() + " milliseconds");
        }

在页面Head部分加入初始时间
引用 
<script language=javascript>
var t1 = new Date().getTime();
</script>
在Body中加入
引用 
<SCRIPT LANGUAGE="JavaScript">
window.onload = function()
{
document.getElementById("TimeShow").innerHTML = "加载本页耗时 "+ (new Date().getTime()-t1) +" 毫秒";
}
</SCRIPT>
在需要显示的地方插入一个ID为TimeShow的标签即可
引用 
<div id="TimeShow"></div>

protected DateTime dt;
        protected void Page_Load(object sender, EventArgs e)
        {
            
        }
        protected override void OnPreInit(EventArgs e)
        {
            dt = DateTime.Now;
            base.OnPreInit(e);
        }

        protected override void OnLoadComplete(EventArgs e)
        {
            base.OnLoadComplete(e);
            TimeSpan ts = DateTime.Now - dt;
            Response.Write("加载页面用时：" + ts.TotalMilliseconds);
        }

 public class UrlReWrite : IHttpModule
    {
        private DateTime start;
        private DateTime end;
        public UrlReWrite()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }

        #region IHttpModule 成员

        public void Dispose()
        {
            throw new Exception("The method or operation is not implemented.");
        }

        public void Init(HttpApplication context)
        {
            context.BeginRequest += new EventHandler(Begin_Request);
            context.EndRequest += new EventHandler(End_Request);
        }

        #endregion

        private void Begin_Request(object sender, EventArgs e)
        {
            start = DateTime.Now;
            //HttpApplication app = sender as HttpApplication;
            //string currentUrl = app.Context.Request.RawUrl;
            //string newUrl = Common.GeneratePhysical(currentUrl);
            //app.Context.RewritePath(newUrl);
        }

        private void End_Request(object sender, EventArgs e)
        {
            HttpApplication app = sender as HttpApplication;
            end = DateTime.Now;
            TimeSpan t = end - start;
            app.Context.Response.Write(string.Format("<!-- Server:{0} now:{1} exec time: {2}-->", app.Context.Server.MachineName,DateTime.Now, t));
        }