一个无刷新效果定时自动更新页面的例子
日期：2011-01-25 浏览次数：20436 次
一个无刷新效果定时自动更新页面的例子(ASP.NET2.0-应用xmlhttp)
首先在ASP.Net创建两个WebForm页，分别命名为Default1，Default2。下面给出代码清单：
//Default1.aspx
<%@ Page Language="C#" Debug="true" AutoEventWireup="true" CodeFile="Default1.aspx.cs" Inherits="Default1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html Xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页</title>
<script type="text/javascript">
var XmlHttp;
function createXmlHttpRequest()
{
if (window.XmlHttpRequest)
{
XmlHttp = new XmlHttpRequest();
}
else if (window.ActiveXObject)
{
try
{
XmlHttp = new ActiveXObject("MsXml2.XmlHTTP");
}
catch (e1)
{
try
{
XmlHttp = new ActiveXObject("Microsoft.XmlHTTP");
}
catch (e2)
{}
}
}
return XmlHttp;
}
function doStart() {
createXmlHttpRequest();
var url = "Default2.aspx?task=reset";
XmlHttp.open("POST", url, true);
XmlHttp.onreadystatechange = startCallback;
XmlHttp.send(null);
}
function startCallback() {
if (XmlHttp.readyState == 4) {
if (XmlHttp.status == 200) {
setTimeout("pollServer()", 1000);
refreshTime();
}
else {
alert("HTTP error: "+XmlHttp.status);
}
}
}
function pollServer() {
createXmlHttpRequest();
var url = "Default2.aspx?task=foo";
XmlHttp.open("POST", url, true);
XmlHttp.onreadystatechange = pollCallback;
XmlHttp.send(null);
}
function refreshTime(){
var time_span = document.getElementById("time");
var time_val = time_span.innerHTML;
var int_val = parseInt(time_val);
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