如何创建和使用XMLHttpRequest对象

Question

如何创建和使用XMLHttpRequest对象

Answer 1

这里有个简单的例程：1，创建并获取XMLHttpRequest对象：function getXMLHttpRequest(){var http_request = false;if (window.XMLHttpRequest){http_request = new XMLHttpRequest();if (http_request.overrideMimeType){http_request.overrideMimeType('text/xml');}}else if (window.ActiveXObject){try{http_request = new ActiveXObject("Msxml2.XMLHTTP");}catch (e){try{http_request = new ActiveXObject("Microsoft.XMLHTTP");}catch (e){}}}if (!http_request){alert('Giving up :( Cannot create an XMLHTTP instance');return false;}return http_request;}2，使用XMLHttpRequest发送请求并处理数据：function make_request(url){http_request = getXMLHttpRequest();if (http_request){http_request.onreadystatechange = function (){//调用自己的方法（获取数据http_request.responseText）//如：alertContents(http_request);};http_request.open('GET', url, true);http_request.send(null);}}此函数为上面的方法调用：function alertContents(http_request){if (http_request.readyState == 4){if (http_request.status == 200){parse_data(http_request.responseText);}}}