前端代码：
<script type="text/javascript">
var xmlHttp;
function createXMLHttpRequest(){
if(window.ActiveXObject){
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
}
}
function start(){
createXMLHttpRequest();
var url="getTime.php";
xmlHttp.open("GET",url,true);
xmlHttp.onreadystatechange = callback;
xmlHttp.send(null);
}
function callback(){
if(xmlHttp.readyState == 4){
if(xmlHttp.status == 200){
document.getElementById("showtime").innerHTML = xmlHttp.responseText;
setTimeout("start()",1000);
}
}
}
</script>
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=gb2312" />
</head>
<body>
<h1>Ajax动态显示时间</h1>
<input type="button" value="开始显示时间" id="go" onclick="start()" />
<p>当前时间：<font color="red"><span id="showtime"></span></font></p>
</body>
</html>
后端代码：
<?php
header("cache-control:no-cache,must-revalidate");
header("Content-Type:text/html;charset=utf-8");
$showtime = date("北京时间Y年m月d日H:i:s");
echo $showtime;
?>
时间： 2024-12-18 14:46:45