利用ICallbackEventHandle实现类似AJAX的无刷新页面_[Asp.Net教程]























先看MSDN Library 2005上的这个例子！

------ ClientCallback.aspx ------
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ClientCallback.aspx.cs" ­ Inherits="ClientCallback" %>

onclick="CallServer('argument', 'context')"/>

-------- ClientCallbacp.aspx.cs -----------

// ClientCallback.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;­
using System.Web.UI.HtmlControls;

public partial class ClientCallback : System.Web.UI.Page, System.Web.UI.ICallbackEventHandle­ r
{

void Page_Load(object sender, EventArgs e)
{
ClientScriptManager cm = Page.ClientScript;
String cbReference = cm.GetCallbackEventReference(this,­ "arg", "ReceiveServerData", "");
String callbackScript = "function CallServer(arg, context) {" + cbReference + "; }";
cm.RegisterClientScriptBlock(this.­ GetType(), "CallServer", callbackScript, true);
}

private string returnStr;
//function called by client, executed on server
public void RaiseCallbackEvent(String eventArgument)
{
//do something with return argument
returnStr = eventArgument.ToUpper();
return;
}

//function that sends result?
public string GetCallbackResult()
{
return returnStr;
}
}

客户端用ReceiveServerData接收服务器返回的数据，

使用CallServer('argument', 'context')传递数据到服务器。

客户端ok了，接下来是服务器端，实现ICallbackEventHandle­ 接口，

private string returnStr;
public void RaiseCallbackEvent(String eventArgument)
{
returnStr = eventArgument.ToUpper();
return;
}

public string GetCallbackResult()
{
return returnStr;
}

最后，将客户端方法和服务器端的方法关联起来，在Page_Load中实现，

ClientScriptManager cm = Page.ClientScript;
String cbReference = cm.GetCallbackEventReference(this,­ "arg", "ReceiveServerData", "");
String callbackScript = "function CallServer(arg, context) {" + cbReference + "; }";
cm.RegisterClientScriptBlock(this.­ GetType(), "CallServer", callbackScript, true);

大功告成！

这种方法也能达到类似ajax的无刷新页面，而且实现起来十分简单。

来源：博客园