用ICallbackEventHandler實現客戶端與服務器端異步

     頁面代碼:
  <script type=text/javascript>
   function ReceiveServerData(rValue)
   {
   alert(rValue);
   }
   </script>
  <input id=Button type=button value=button onclick =CallServer(Client) />
  服務端代碼:
  public partial class back : SystemWebUIPageSystem Web UI ICallbackEventHandler
  {
   public string CallBackValue = null;
   protected void Page_Load(object sender EventArgs e)
   {
  
   }
   // 注冊腳本到前台頁面
   protected void Page_PreRender(object sender EventArgs e)
   {
   RegClientScript();
   }
   // javascript函數(服務器端事件的客戶端回調)
   protected void RegClientScript()
   {
   ClientScriptManager cs = PageClientScript;
   string jstxt=@
   function CallServer(msgid)
   {
   + csGetCallbackEventReference(this msgid ReceiveServerData null) + @;
   };
   csRegisterStartupScript(thisGetType() callserver jstxt true);
   }
   //ICallbackEventHandler接口
   //把值傳到前台
   string ICallbackEventHandlerGetCallbackResult()
   {
   return CallBackValue + Server;
   }
  
   //按受前台的參數
   void ICallbackEventHandlerRaiseCallbackEvent(string eventArgument)
   {
   thisCallBackValue = eventArgument;
   }
  }
  
From:http://tw.wingwit.com/Article/program/net/201311/13328.html