使用XmlHttpRequest对象发送一次ajax请求

使用XMLHttpRequest object对象发送一次ajax请求

XMLHttpRequest对象中的open方法

open(“method”, “URL”[, asyncFlag[, “userName”[, “password”]]])

property	description
method	The HTTP method used to open the connection, such as GET, POST, PUT, HEAD,or PROPFIND.
URL	The requested URL.
asyncFlag	A Boolean value indicating whether the call is asynchronous. The default is true.
userName	The username of your account.
password	The password used to connect to your account.

XMLHttpRequest对象中的readyState和status的属性，The readyState property tells you how the data downloading is going,The status property is the property that contains the actual status of the download. This is actually the normal HTTP status code that you get when you try to download web pages,readyState状态：

value	description
0	Uninitialized
1	Loading
2	Loaded
3	Interactive
4	Complete

具体代码：

function createXmlHtttpRequestObj() {
var XmlHttpRequestObj = false;
if (window.XMLHttpRequest){
XmlHttpRequestObj = new XMLHttpRequest();
//for ie...
}else if (window.ActiveXObject){
XmlHttpRequestObj = new ActiveXObject("Microsoft.XMLHTTP");
}
return XmlHttpRequestObj;
}

function getData(url) {
var XmlHttpRequestObj = createXmlHtttpRequestObj();
if (XmlHttpRequestObj){
XmlHttpRequestObj.open("GET",url);
XmlHttpRequestObj.onreadystatechange = function () {
if ((XmlHttpRequestObj.readyState == 4) && (XmlHttpRequestObj.status == 200)){
var responseText = XmlHttpRequestObj.responseText;
layer.msg("ajax获取数据: "+ responseText);
}
};
XmlHttpRequestObj.send(null);
}else {
layer.msg("您的网站不支持ajax");
}
}