Ajax封装

var req; function createXMLHttpRequest(){//创建XMLHttpRequest对象 var request; if(window.XMLHttpRequest){ request=new XMLHttpRequest(); }else if(window.ActiveXObject){ request=new ActiveXObject("Msxml2.XMLHTTP"); } return request; } function test(method,url,param,Asyhc,handle200,handle404,handle500,locading){ var req=createXMLHttpRequest();//创建XMLHttpRequest对象 req.onreadystatechange=function(){//处理返回数据 if(4==req.readyState){//服务器已经成功接收数据 if(200==req.status){//成功返回数据 handle200(req);//一个函数也是一个对象 }else if(404==req.status){ handle404(req); }else if(500==req.status){ handle500(req); } }else{ locading(req); } } if("get".equals(method.toLowerCase)){//判断是get还是post方法 req.open("get",url+(param==null?"":"?"+param),Asyhc); req.send(null); }else if("post".equals(method.toLowerCase)){ req.open("post",Asyhc); req.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); req.send(param); } }