ajax在asp.net总的简单应用问题

三笑咖啡 2007-04-27 01:55:59

以前在asp中用过一点ajax.很简单那种如:
res.asp文件
<%
dim mesid
mesid=request.querystring("mid")
response.write mesid&time()
%>

req.htm文件
<script language="javascript">
var receiveReq=createAjaxObj();
var mTimer;
var i=1;
function createAjaxObj()
{
var httprequest=false;
if(window.XMLHttpRequest)
{
httprequest=new XMLHttpRequest();
}
else if(window.ActiveXObject)
{
try{
httprequest=new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e){
try{
httprequest=new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e){}
}
}
return httprequest
}

function getChatText(){
if(receiveReq.readyState==4||receiveReq.readyState==0){
var submitURL="res.asp?mid="+i;
receiveReq.open("get",submitURL,true);
receiveReq.onreadystatechange=handleReceiveChat;
receiveReq.send(null);

i++;
}
}

function handleReceiveChat(){
if(receiveReq.readyState==4){
var receivemes=receiveReq.responseText;
var showdiv=document.getElementById("showmes");
showdiv.innerHTML=receivemes;

mTimer=setTimeout('getChatText()',2000);
}

}
</script>
</head>
<body onload="getChatText()">
<div id="showmes">no mes receive</div>

可以每阁2秒访问一次res.asp,所以显示时间是可以变化的,也就是动态的.

现在想在asp.net中也实现类似的功能.
可是却不行.
req.htm文件一样的
res.aspx文件为:
<script language="c#" runat="server">
public void Page_Load(object sender,EventArgs e)
{
Application.Lock();
Application["num"]=(int)(Application["num"])+1;
Application.UnLock();
Page.Response.Write(Application["num"].ToString());
}
</script>
//Application["num"]已经初始化了.
req.htm显示的内容不是动态的
只有在单独刷新res.aspx文件后,req.htm中显示的内容才改变一下
不知道怎样实现.

还有就是csdn的短消息,好象是及时通知的.不知道怎样实现.有没有简单示例代码.

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