一个简单的微软CallBack例子。

aspx:<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Test.aspx.cs" Inherits="MorningSun.Web.Test" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title></title>
    
    <script language="Javascript" type="text/javascript">
        /* 本段函数用于实现与服务器的异步通讯 */
        function CallServer(arg){
            <%=ClientScript.GetCallbackEventReference(this, "arg", "JsServerBackSucess", null, "JsServerBackError", false) %>
        }
        // 服务器运行成功时，执行的js函数
        function JsServerBackSucess(argServerBack){
            if(argServerBack!=""){
                document.getElementById("lblTest").innerText=argServerBack;
            }
        }
        // 服务器运行出错时，执行的js函数
        function JsServerBackError(argServerBack){
           alert(argServerBack);
        }
        
        
        function getText(){
            CallServer(document.getElementById("txtTest").value);
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <input type="text" id="txtTest" runat="server"/>
        <input type="button" id="btnTest" runat="server" value="测试" onclick="getText();" />
        <label id="lblTest" runat="server"></label>
    </div>
    </form>
</body>
</html>aspx.cs:using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;namespace MorningSun.Web
{
    public partial class Test : System.Web.UI.Page, ICallbackEventHandler
    {
        protected void Page_Load(object sender, EventArgs e)
        {
        }        #region ICallbackEventHandler 成员
        private string callBackStr = string.Empty;
        public string GetCallbackResult()
        {
            return callBackStr;
        }        public void RaiseCallbackEvent(string eventArgument)
        {
            callBackStr = processChars(eventArgument);
        }        
        #endregion        private string processChars(string str)
        {
            return str + ":-)";
        }
    }
}