本文实例讲述了jQuery实现向下滑出的平滑下拉菜单效果。分享给大家供大家参考。具体如下：
这里演示的jQuery向下滑出的下拉平滑菜单，可添加多个菜单选项，修改起来比较灵活的下滑菜单，颜色风格自己可修改，不多介绍了，感兴趣的运行一下代码看效果。
代码如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="https://www.w3.org/1999/xhtml">
<head>
<title>jquery缓冲下拉导航菜单特效</title>
<script type="text/javascript" src="jquery-1.6.2.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("ul.subnav").parent().append("<span></span>");
$("ul.topnav li span").mouseover(function() {
$(this).parent().find("ul.subnav").slideDown('fast').show();
$(this).parent().hover(function() {
}, function(){
$(this).parent().find("ul.subnav").slideUp('slow');
});
}).hover(function() {
$(this).addClass("subhover");
}, function(){
$(this).removeClass("subhover");
});
});
</script>
<style>
body,form,ul{margin:0px; padding:0px;}
body{font-size:12px;}
.clear{clear:both}
div.examples_body {
width: 750px;
margin: 50px auto;
}
h2.title_name {
font-family: normal Georgia,'Times New Roman',Times,serif;
font-weight: normal;
font-size: 4em;
padding: 50px 0 20px 0;
text-align: center;
}
h2.title_name span {
font-family: normal Georgia,'Times New Roman',Times,serif;
color: #AAA;
font-size: 0.9em;
}
h2.title_name small {
color: #AAAAAA;
display: block;
font-family: normal Verdana,Arial,Helvetica,sans-serif;
font-size: 0.2em;
letter-spacing: 1.0em;
text-transform: uppercase;
}
div.examples_body h3 {
color: #555;
font-size: 130%;
padding-bottom: 15px;
margin-bottom: 15px;
}
p.demo_btn {
width: 750px;
margin: 30px auto;
font-size: 0;
text-indent: -9999px;
clear: both;
overflow: hidden;
}
p.demo_btn a {
width: 160px;
height: 41px;
float: right;
background: url(images/Download_Button.gif) no-repeat;
}
p.demo_btn a:hover {
background: url(images/Download_Button_o.gif) no-repeat;
}
div.examples_body_wrap h3 {
color: #f9f66d;
font-size: 130%;
padding-bottom: 15px;
margin-bottom: 15px;
background: url(images/solid-line-news.gif) repeat-x bottom;
}
div.examples_body_wrap {
width: 750px;
margin: 50px auto 0 auto;
clear: both;
}
ul.topnav {
width: 710px;
float: left;
background: #222;
background: url(images/topnav_bg.gif) repeat-x;
}
ul.topnav li {
float: left;
margin: 0;
padding: 0 10px 0 15px;
position: relative;
display: inline;
}
ul.topnav li a {
padding: 10px 5px;
color: #fff;
display: block;
text-decoration: none;
float: left;
}
ul.topnav li a:hover {
-moz-border-radius: 3px;
-khtml-border-radius: 3px;
-webkit-border-radius: 3px;
}
ul.topnav li span {
width: 17px;
height: 35px;
float: left;
background: url(images/subnav_btn.gif) no-repeat center top;
}
ul.topnav li span.subhover {
background-position: center bottom; cursor: pointer;
}
ul.topnav li ul.subnav {
width: 170px;
position: absolute;
left: 0; top: 35px;
background: #333;
margin: 0; padding: 0;
display: none;
float: left;
border: 1px solid #111;
}
ul.topnav li ul.subnav li{
width: 170px;
margin: 0; padding: 0;
border-top: 1px solid #252525;
border-bottom: 1px solid #444;
clear: both;
}
html ul.topnav li ul.subnav li a {
width: 145px;
float: left;
background-color: #333;
padding-left: 20px;
font-size: 0.9em;
}
html ul.topnav li ul.subnav li a:hover {
background-color: #222;
}
</style>
</head>
<body>
<div class="examples_body">
<ul class="topnav">
<li><a href="#">下拉菜单0</a></li>
<li>
<a href="#">下拉菜单1</a>
<ul class="subnav">
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
</ul>
</li>
<li>
<a href="#">下拉菜单2</a>
<ul class="subnav">
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
</ul>
</li>
<li><a href="#">下拉菜单3</a>
<ul class="subnav">
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
<li><a href="#">下拉子菜单</a></li>
</ul>
</li>
<li><a href="#">下拉菜单4</a></li>
<li><a href="#">下拉菜单5</a></li>
</ul>
<!-- Examples body -->
</div>
<div class="clear"></div>
</body>
</html>
