                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /DOM事件探秘

為什么<span>標(biāo)簽沒有設(shè)置display:block，還能設(shè)置寬高？

<!doctype?html>
<html>
<head>
????<meta?charset="UTF-8">
<title>Document</title>
<style>
*{margin:0;padding:0;}
?????.head{font-size:12px;padding:6px?0?0?10px;}
?????#login_box{width:300px;height:150px;background:#eee;
?????border:1px?solid?#ccc;position:absolute;left:50%;top:50%;margin-left:-150px;margin-top:-75px;display:none;}
?????#login_box?p{height:20px;border-bottom:1px?solid?#ccc;font-size:12px;padding:6px?0?0?5px;font-weight:bold;}
?????#close{width:14px;height:14px;background:url(close.png)?no-repeat;position:absolute;right:4px;top:6px;}
</style>
<script>
??????window.onload=function(){
???????var?login_btn=document.getElementById('login'),
???????????login_box=document.getElementById('login_box'),
???????????close=document.getElementById('close');
???????//?封裝添加事件監(jiān)聽程序
????????function?addEvent(ele,type,hander){
???????????//?執(zhí)行代碼
???????????if(ele.addEventListener){
???????????????ele.addEventListener(type,hander,false);
???????????}?else?if(ele.attachEvent){
???????????????ele.attachEvent('on'+type,hander);
???????????}?else?{
???????????????ele['on'+type]=hander;
???????????}
???????}
????????//?顯示登錄層函數(shù)
???????function?showLogin(){
???????//?執(zhí)行代碼
????????????login_box.style.display='block'?
????????}
????????//?隱藏登錄層函數(shù)
????????function?hideLogin(){
??????????//?執(zhí)行代碼
??????????login_box.style.display='none'?
????????}
????????//點(diǎn)擊登錄按鈕顯示登錄層?
????????//?執(zhí)行代碼
????????addEvent(login_btn,'click',showLogin);
????????//點(diǎn)擊關(guān)閉按鈕隱藏登錄層
????????//?執(zhí)行代碼
????????addEvent(close,'click',hideLogin);}
??????
</script>
</head>
<body>
<div>親，您好！<input?type="button"?value="登?錄"?id="login"></div>
<div?id="login_box">
<p>用戶登錄</p><span?id="close">X</span>
</div>
</body>
</html>