欢迎访问: www.ptcms.cnajax中常用的三种数据格式分别为xml, text, json(JavaScript Object Notation)。特地将其用例结合起来，如下：
<html><head><script>var xmlHttp;function createXMLHttpRequest(){ if(window.ActiveXObject){ xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } else if(window.XMLHttpRequest){ xmlHttp = new XMLHttpRequest(); }}function xmlReq(){ createXMLHttpRequest(); xmlHttp.onreadystatechange = xmlhandle; xmlHttp.open("GET", "data.xml", true); xmlHttp.send(null); //发送请求}function xmlhandle(){ if(xmlHttp.readyState == 4){ if (xmlHttp.status == 200 || xmlHttp.status == 0){ var xmlDOM = xmlHttp.responseXML;// 取得XML的DOM对象 var root = xmlDOM.documentElement; var info = root.getElementsByTagName('info');// 取得<info>结果 alert("XML's value: " + info[0].firstChild.data); } }}function txtReq(){ createXMLHttpRequest(); xmlHttp.onreadystatechange = txthandle; xmlHttp.open("GET", "data.txt", true); xmlHttp.send(null); //发送请求}function txthandle(){ if(xmlHttp.readyState == 4){ if (xmlHttp.status == 200 || xmlHttp.status == 0){ alert("Text's value: " + xmlHttp.responseText); } }}function jsonReq(){ createXMLHttpRequest(); xmlHttp.onreadystatechange = jsonhandle; xmlHttp.open("GET", "data.txt", true); xmlHttp.send(null); //发送请求}function jsonhandle(){ if(xmlHttp.readyState == 4){ if (xmlHttp.status == 200 || xmlHttp.status == 0){ var resp = xmlHttp.responseText;// 构造返回JSON对象的方法 var func = new Function("return "+resp); var json = func();// 得到JSON对象 alert("JSON's value: " + json.info + "(" + json.version + "v)"); } }}</script><title>Ajax Hello World</title></head><body><input type="button" value="XML" onclick="xmlReq();" /><input type="button" value="Text" onclick="txtReq();" /><input type="button" value="JSON" onclick="jsonReq();" /></body></html>
其中用到的data.txt:
{info: "hello weixq!",version: "2.0"}
data.xml:
<?xml version="1.0" encoding="GB2312" ?> <root> <info>hello world!</info></root>
