<title>構(gòu)造函數(shù)</title><script>$ = document.getElementById;function news() {this.divid = "";this.get = function(divid) {xmlHttp = this.GetXmlHttpObject();if (xmlHttp==null) {alert ("您的瀏覽器不支持AJAX！");return;}this.divid = divid;//this.get_Changed();var url = "news.php";xmlHttp.open("GET", url, true);xmlHttp.onreadystatechange=this.get_Changed;xmlHttp.send(null);},this.get_Changed = function() {if (xmlHttp.readyState==4) {str = xmlHttp.responseText;$(this.divid).innerHTML = str;alert(this.divid) //為什么this.divid 為undefine呢}}this.GetXmlHttpObject = function() {var xmlHttp=null;try { // Firefox, Opera 8.0+, SafarixmlHttp=new XMLHttpRequest();}catch (e) { // Internet Explorertry {xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");}catch (e) {xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");}}return xmlHttp;}}var News = new news();News.get("aa"); //在aa中加載news.php的內(nèi)容</script></head><body><div id="aa"></div></body>已經(jīng)解決了，確實(shí)是作用域的問(wèn)題，謝謝拋磚引玉用_this就搞定了function news() {var _this = this;this.divid = "";this.get = function(divid) {……xmlHttp.open("GET", url, true);xmlHttp.onreadystatechange=this.get_Changed;xmlHttp.send(null);},this.get_Changed = function() {if (xmlHttp.readyState==4) {str = xmlHttp.responseText;$(_this.divid).innerHTML = str;alert(_this.divid);}}}
如下代碼中，為什么在ajax的構(gòu)造函數(shù)中，this.XX值變成未定義了呢？
幕布斯7119047
2022-03-04 07:07:44
