Ajax请求演示-优快云博客

<?php if(isset($_GET['do']) && $_GET['do']==='ajax') { exit("{msg:'Hello World!'}"); } ?> <!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> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Ajax Demo</title> <script type="text/javascript"> function readyStateChangeHandle(xhr) { // 具体操作,需要了解一下JavaScript的相关知识 eval('var result='+xhr.responseText); window.alert(result.msg); } function Ajax() { // 创建异步请求对象 var xhr=window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest(); // 判断一下对象是否创建成功 if(!xhr) { return false; } // 设置异步请求处理函数(这里用匿名函数而不直接用定义好的函数,主要是方便传递参数) xhr.onreadystatechange=function(){ // readyState有4种状态(0=UNINITIALIZED,1=LOADING,2=LOADED,3=INTERACTIVE,4=COMPLETED) if(xhr.readyState==4) { // status实际上就是HTTP状态码 if(xhr.status==200) { readyStateChangeHandle(xhr); } } }; xhr.open("GET","ajax.php?do=ajax",true); xhr.send(null); } </script> </head> <body> <button type="button" onclick="Ajax();">Ajax</button> </body> </html>

最简单的Ajax入门例程