基于jquery的大众点评，分类导航实现代码

        简单   轻盈    快速    高效！

html结构：

<div id="menu"> 
<ul id="G_chan-panel" class="pop-panel pp_channels Fix" style="position: absolute; visibility: visible; z-index: 1001; top: 175px; left: 189px; "> 
<li class="root-item "> <a href="#" class="root-name"><span>餐饮</span></a> 
<ul class="pop-panel Fix sub-list"> 
<li class="main-cate"><a href="#">餐饮频道</a></li> 
<li><a href="#">粤菜</a></li> 
... 
</ul> 
</li> 
<li class="root-item"> <a href="#" class="root-name"><span>购物</span></a> 
<ul class="pop-panel Fix sub-list"> 
<li class="main-cate"><a href="#">购物频道</a></li> 
<li><a href="#">超市/便利店</a></li> 
... 
<li><a href="#">其他</a></li> 
</ul> 
</li> 
</ul> 
</div>

jquery代码：

<script type="text/javascript"> 
$(function () { 
$('#G_chan-panel').delegate("li", "mouseenter", function () { $(this).addClass("active") }); 
$('#G_chan-panel').delegate("li", "mouseleave", function () { $(this).removeClass("active") }); 
}); 
</script>

css样式：

BODY { 
background-color:#fff; 
color:#555; 
font: 9pt/14px Tahoma, "宋体", Arial, Helvetica, Sans-Serif; 
letter-spacing: 0; 
margin: 0; 
} 
html, body, ul, ol, li, dl, dt, dd, p, h1, h2, h3, h4, h5, h6, a, img, th, td, form, fieldset, iframe, object, pre, code, legend, blockquote { 
border: 0 none; 
margin: 0; 
outline: 0 none; 
padding: 0; 
} 
h1, h2, h3, h4, h5, h6 { 
font-size: 100%; 
font-weight: normal; 
} 
UL, LI { 
list-style: none outside none; 
margin: 0; 
padding: 0; 
} 
IMG { 
border: medium none; 
margin: 0; 
padding: 0; 
cursor:pointer; 
} 
input, img, select { 
vertical-align: middle; 
} 
A { 
color: #666666; 
} 
A:link { 
color: #666666; 
text-decoration: none; 
} 
A:visited { 
color: #666666; 
text-decoration: none; 
} 
A:hover { 
color: #C90809; 
text-decoration: none; 
} 
/*导航*/ 
.pp_channels .root-item, .pp_channels .root-name, .pp_channels .root-name span, .pp_channels .sub-list li a { 
background-image: url("bg.png"); 
background-repeat: no-repeat; 
} 
.G_chan-panel { 
position: absolute; 
z-index: 1000; 
top: 120px; 
left: 199px; 
visibility: hidden; 
} 
.pp_channels { 
width: 138px; 
padding: 0; 
border-width: 0 0 2px 1px; 
border-radius: 5px; 
-webkit-border-radius: 5px; 
-moz-border-radius: 5px; 
-moz-box-shadow: -1px 1px 1px #ccc; 
-webkit-box-shadow: 0 1px 5px #ccc; 
box-shadow: 0 1px 5px #ccc; 
} 
.pp_channels .root-item { 
zoom: 1; 
position: relative; 
width: 139px; 
height: 34px; 
background-position: -13px -373px; 
overflow: visible; 
vertical-align: middle; 
} 
.pp_channels .root-name { 
display: block; 
z-index: 1001; 
position: relative; 
border-top:1px solid #B9F5D2; 
padding-left: 10px; 
background-position: -10px -358px; 
cursor: pointer; 
} 
.pp_channels .root-name span { 
display: block; 
border-right: 1px solid #B9F5D2; 
padding-left: 9px; 
height: 34px; 
font-size: 1.2em; 
line-height: 34px; 
color: #000; 
background-position: -167px -358px; 
} 
.pp_channels .active .root-name { 
background: #fff; 
} 
.pp_channels .active .root-name span { 
color: #C00; 
border-color: #fff; 
} 
.pp_channels .no-sub .root-name span { 
border-color: #fff; 
background-position: 20px -358px; 
} 
.pp_channels .sub-list { 
left: 138px; 
top: -34px; 
padding: 5px 2px 5px 16px; 
width: 200px; 
overflow: hidden; 
_top: -35px; 
-moz-box-shadow: -1px 1px 1px #ccc; 
-webkit-box-shadow: 0 1px 5px #ccc; 
box-shadow: 0 1px 5px #ccc; 
} 
.pp_channels .active .sub-list { 
visibility: visible; 
} 
.pp_channels .sub-list li { 
float: left; 
width: 83px; 
margin: 0 10px 5px 0; 
} 
.pp_channels .sub-list .main-cate { 
width: 200px; 
margin-right: -10px; 
font-weight: bold; 
} 
.pp_channels .sub-list a { 
padding-left: 3px; 
line-height: 21px; 
background-position: -169px -418px; 
*background-position: -169px -420px; 
} 
.pp_channels .sub-list a: hover { 
background-position: -169px -438px; 
*background-position: -169px -440px; 
} 
.pop-panel { 
z-index: 1000; 
position: absolute; 
visibility: hidden; 
border: 1px solid #B9F5D2; 
padding: 5px 9px; 
background: #fff; 
color: #61646E; 
#margin-left:-0px; 
_margin-left:-0px; 
} 
.pop-panel a { 
color: #61646E; 
} 
.pop-panel a: hover { 
text-decoration:none; 
color: #C00; 
}

其他一些应用：

//定位 
var X = $('#G_chan').offset().top; 
var Y = $('#G_chan').offset().left; 
$("#G_chan-panel").offset({ top: X + 36, left: Y - 5 }); 
//鼠标经过 动画效果 防点击链接跳转 
$("#G_chan").hover(function (event) { 
event || event.stopPropagation(); $("#G_chan-panel").slideDown().mouseleave(function () { 
$(this).slideUp() 
}); 
}); 
//点击 城市列表 下拉动画 防冒泡 
$("#G_loc").click(function (event) { event.preventDefault(); $("#G_loc-panel").slideToggle("slow"); });作者：曾祥展