AJAX 带有 取消功能的 UpdateProgress

aspx 页 :

< html xmlns = " http://www.w3.org/1999/xhtml "   >
< head runat = " server " >
     < title > 无标题页 </ title >
< script language = " javascript "  type = " text/javascript " >  
<!--  
function CancelAsyncPostBack() { 
var prm  =  Sys.WebForms.PageRequestManager.getInstance(); 
if  (prm.get_isInAsyncPostBack()) { 

prm.abortPostBack(); 

} 
} 
//  --> 
</ script >  
< style type = " text/css " >

#UpdatePanel1 {}{

  width:200px; height:100px;

  border: 1px solid gray;

}

#UpdateProgress1 {}{

  width:200px; background - color: #FFC080;

  bottom:  0 % ; left: 0px; position: absolute;

}

</ style >
</ head >
< body >
     < form id = " form1 "  runat = " server " >
     < div >
         < table style = " width: 835px; height: 391px " >
             < tr >
                 < td style = " width: 100px " >
                 </ td >
                 < td style = " width: 100px " >
                 </ td >
                 < td style = " width: 100px " >
                 </ td >
             </ tr >
             < tr >
                 < td style = " width: 100px " >
                 </ td >
                 < td style = " width: 100px " >
                     < asp:ScriptManager ID = " ScriptManager1 "  runat = " server " >
                     </ asp:ScriptManager >
                     < asp:UpdatePanel ID = " UpdatePanel1 "  runat = " server " >
                         < ContentTemplate >
                             < asp:Button ID = " Button1 "  runat = " server "  OnClick = " Button1_Click "  Text = " Button "   />
                             < asp:Label ID = " Label1 "  runat = " server "  Text = " 页面初始化 " ></ asp:Label >
                         </ ContentTemplate >
                     </ asp:UpdatePanel >
                     < asp:UpdateProgress ID = " UpdateProgress1 "  runat = " server " >
                         < ProgressTemplate >
                            正在处理数据，请稍候. < br  />
                             < input id = " input1 "  type = " button "  value = " 取消 "  onclick = " CancelAsyncPostBack() " />
                         </ ProgressTemplate >
                     </ asp:UpdateProgress >
                 </ td >
                 < td style = " width: 100px " >
                 </ td >
             </ tr >
             < tr >
                 < td style = " width: 100px " >
                 </ td >
                 < td style = " width: 100px " >
                 </ td >
                 < td style = " width: 100px " >
                 </ td >
             </ tr >
         </ table >
    
     </ div >
     </ form >
</ body >
</ html >

aspx.CS :

  protected   void  Button1_Click( object  sender, EventArgs e)
    {
        System.Threading.Thread.Sleep( 3000 );  // 人为的创建一个3秒钟的延迟并显示当前时间

        Label1.Text  =   " Page refreshed at  "   +

            DateTime.Now.ToString();

    }