ASP.NET2.0中用ICallbackEventHandler實現客戶端與服務器端異步交互

頁面代碼:
<script type="text/Javascript">
      function ReceiveServerData(rValue)
      {
         alert(rValue);
      }
 </script>
<input id="Button1" type="button" value="button" onclick ="CallServer('ClIEnt')" />
服務端代碼:
public partial class back2 : System.Web.UI.Page,System .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 = Page.ClIEntScript;
       string JStxt=@"
                  function CallServer(msgid)
                  {
                     " + cs.GetCallbackEventReference(this, "msgid", "ReceiveServerData", null) + @";
                  }";
       cs.RegisterStartupScript(this.GetType(), "callserver", JStxt, true);
    }
    //ICallbackEventHandler接口
    //把值傳到前台
    string ICallbackEventHandler.GetCallbackResult()
    {
        return CallBackValue + ",Server";
    }

    //按受前台的參數
    void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
    {
        this.CallBackValue = eventArgument;
    }
}