<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<style>
*{
margin: 0;
padding: 0;
}
.nav{
list-style: none;
width: 300px;
margin: 100px auto;
}
.nav > li{
border: 1px solid #000;
line-height: 35px;
border-bottom: none;
text-indent: 2px;
position: relative;
}
.nav li:last-child{
border-bottom: 1px solid #000;
border-bottom-left-radius: 10px;
border-bottom-right-radius: 10px;
}
.nav li:first-child{
border-top-left-radius: 10px;
border-top-right-radius: 10px;
}
.nav >li > span{
display: inline-block;
background-image: url(./img/right.png) ;
width: 32px;
height:32px ;
position: absolute;
right: 10px;
top: 5px;
}
.sub >li{
list-style: none;
border-bottom: 1px solid white;
}
.sub >li:hover{
background: red;
}
.nav > .current >span{
transform: rotate(90deg);
}
.sub{
display: none;
}
</style>
<body>
<ul class="nav">
<li class="">一級菜單<span></span>
<ul class="sub">
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
</ul>
</li>
<li>一級菜單<span></span>
<ul class="sub">
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
</ul>
</li>
<li>一級菜單<span></span>
<ul class="sub">
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
</ul></li>
<li>一級菜單<span></span>
<ul class="sub">
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
</ul></li>
<li>一級菜單<span></span>
<ul class="sub">
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
</ul></li>
<li>一級菜單<span></span>
<ul class="sub">
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
<li>二級菜單</li>
</ul></li>
</ul>
</body>
<script src="./jquery.js"></script>
<script>
$(function () {
//1.監聽一級菜單的點擊事件
$(".nav > li").click(function () {
//1.1拿到二級菜單
var $sub =$(this).children(".sub")
//1.2讓二級菜單展開
$sub.slideDown(1000);
//1.3拿到因此非當前二級菜單
var $otherSub =$(this).siblings().children(".sub")
//1.4讓因此非當前二級菜單收起
$otherSub.slideUp(1000)
//1.5讓被點擊的一級菜單箭頭旋轉
$(this).addClass("current");
//1.6讓非被點擊的一級菜單還原
$(this).siblings().removeClass("current");
})
})
</script>
</html>
效果圖:
