代码文件: using System;using System.Collections;using System.ComponentModel;using System.Data;using System.Drawing;using System.Web;using System.Web.SessionState;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.HtmlControls;using System.Threading;namespace AjaxTest{ /**//// <summary> /// WebForm2 的摘要说明。 /// </summary> public class WebForm2 : System.Web.UI.Page { protected System.Web.UI.WebControls.Button Button1; protected System.Web.UI.WebControls.Label Label1; private void Page_Load(object sender, System.EventArgs e) { Response.Write("<div id='mydiv' >"); Response.Write("_"); Response.Write("</div>"); Response.Write("<script>mydiv.innerText = '';</script>"); Response.Write("<script language=javascript>;"); Response.Write("var dots = 0;var dotmax = 10;function ShowWait()"); Response.Write("{var output; output = '正在装载页面';dots++;if(dots>=dotmax)dots=1;"); Response.Write("for(var x = 0;x < dots;x++){output += '·';}mydiv.innerText = output;}"); Response.Write("function StartShowWait(){mydiv.style.visibility = 'visible'; "); Response.Write("window.setInterval('ShowWait()',1000);}"); Response.Write("function HideWait(){mydiv.style.visibility = 'hidden';"); Response.Write("window.clearInterval();}"); Response.Write("StartShowWait();</script>"); Response.Flush();//这一句是最关键的 } private void Button1_Click(object sender, System.EventArgs e) { //当点击按钮时,假设请求需要较长时间(这里设置为10秒) System.Threading.Thread.Sleep(10000); this.Label1.Text = "终于加载完成啦"; } Web 窗体设计器生成的代码#region Web 窗体设计器生成的代码 override protected void OnInit(EventArgs e) { // // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。 // InitializeComponent(); base.OnInit(e); } /**//// <summary> /// 设计器支持所需的方法 - 不要使用代码编辑器修改 /// 此方法的内容。 /// </summary> private void InitializeComponent() { this.Button1.Click += new System.EventHandler(this.Button1_Click); this.Load += new System.EventHandler(this.Page_Load); } #endregion }} 页面文件: <%@ Page language="c#" Codebehind="WebForm2.aspx.cs" AutoEventWireup="false" Inherits="AjaxTest.WebForm2" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" ><HTML> <HEAD> <title>WebForm2</title> <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1"> <meta name="CODE_LANGUAGE" Content="C#"> <meta name="vs_defaultClientScript" content="JavaScript"> <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> <script> HideWait(); </script> </HEAD> <body MS_POSITIONING="GridLayout"> <form id="Form1" method="post" runat="server"> <FONT face="宋体"> <asp:Button id="Button1" style="Z-INDEX: 101; LEFT: 480px; POSITION: absolute; TOP: 200px" runat="server" Text="Button"></asp:Button> <asp:Label id="Label1" style="Z-INDEX: 102; LEFT: 632px; POSITION: absolute; TOP: 240px" runat="server">Label</asp:Label></FONT> </form> </body></HTML>