展开收缩，用事件代理来写的话怎样写，总是有问题
展开收缩不是那么的顺畅
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<style>
#ul1 {width: 100px; padding: 0;}
#ul1 li {width: 100px; list-style: none;}
#ul1 li h2 {margin: 0; padding: 0; height: 20px; background: #ccc; font-size: 12px; font-weight: normal; text-align: center; line-height: 20px; border: 1px solid #333;}
#ul1 li div {height: 100px; background: red; display: none;}
</style>
</head>
<body>
<ul id="ul1">
<li>
<h2> 1111 </h2>
<div id="a1"></div>
</li>
<li>
<h2> 2222 </h2>
<div id="a2"></div>
</li>
<li>
<h2> 3333 </h2>
<div id="a3"></div>
</li>
<li>
<h2> 4444 </h2>
<div id="a4"></div>
</li>
</ul>
<script>
window.onload=function(){
var ul=document.getElementById('ul1');
var li=ul.getElementsByTagName('h2');
var div=ul.getElementsByTagName('div');
ul.addEventListener('click', function(e){
if(e.target.parentNode.tagName = 'LI'){
for(var i=0; i<div.length; i++){
div[i].style.display = 'none'
}
console.log(e.target.parentNode,e.target.parentNode.getElementsByTagName('div')[0])
var elem = e.target.parentNode.getElementsByTagName('div')[0];
if(elem.show==1){
elem.style.display = 'none'
elem.show=0
}else{
elem.style.display = 'block'
elem.show=1;
}
}
})
};
</script>
</body>
</html>试下jQuery的slideDown() slideUp() 或者 toggle()