Question

高手来看看这段js代码是做什么用的？

if (!httpType) httpType = "GET";
if (window.XMLHttpRequest) {
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {
http_request.overrideMimeType('text/plain');
}
} 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('Cannot send an XMLHTTP request');
return false;
}
var changefunc="http_request.onreadystatechange = "+functionName;
eval (changefunc);
http_request.open(httpType, url, true);
http_request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
http_request.send(sendData);
}

//HTTP 返回值处理 参考
function getReturnedText () {
if (http_request.readyState == 4) {
if (http_request.status == 200) {
alert(http_request.responseText);
}
}
}
function geturl(url,id){
var http=false;
$(id).innerHTML='<span class="loading">  </span>';
if(window.XMLHttpRequest){http=new XMLHttpRequest();if(http.overrideMimeType){http.overrideMimeType('text/plain');}}else if(window.ActiveXObject){try{http=new ActiveXObject("Msxml2.XMLHTTP");}catch(e){try{http=new ActiveXObject("Microsoft.XMLHTTP");}catch(e){}}}
if(!http){alert('Cannot send an XMLHTTP request');return false;}
http.onreadystatechange=function(){if(http.readyState==4){$(id).innerHTML=http.responseText;}}
http.open("get", url, true);
http.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
http.send(null);
}

Answer 1

主要功能在函数
function geturl(url,id)里
是用XMLHTTPRequest来获取一个网页地址的源代码的。
然后显示在id的元素里。

Answer 2

ajax 异步请求