Ajax Js倒计时执行后台方法

HTML代码

 

 1 <% @ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default"  %>
 2
 3 <! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" >
 4 < html  xmlns ="http://www.w3.org/1999/xhtml" >
 5 < head  runat ="server" >
 6      < title > Untitled Page </ title >
 7      < script  language ="javascript"  type ="text/javascript" >
 8    function hello()
 9    {
10        BeginMessage();
11        var t=setTimeout("endMessage('计时结束 5 seconds!')",5000)
12    }
13    function endMessage(msg)
14    {
15        PageMethods.Msg(msg,updateMessages);
16    }
17    function BeginMessage()
18    {
19        PageMethods.Msg("计时开始",updateMessages);
20    }
21    function updateMessages(result)
22    {
23        $get("lbl").innerHTML =result;
24    }
25     </ script >
26 </ head >
27 < body >
28      < form  id ="form1"  runat ="server" >
29          < asp:ScriptManager  ID ="ScriptManager1"  EnablePageMethods ="true"  runat ="server"   />
30          < div >
31              < asp:Label  ID ="lbl"  runat ="server"  Text ="Label" ></ asp:Label
32              >< input  id ="Button1"  type ="button"
33                 value ="开始"  onclick ="hello()"   />
34          </ div >
35      </ form >
36 </ body >
37 </ html >
38

 

 后台代码

 

Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Services;
public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    [WebMethod]
    static public string Msg(string msg)
    {
        return msg; 
    }
}