jQuery实现向下滑出的平滑下拉菜单效果

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。

运行效果截图如下：

在线演示地址如下：

http://demo.jb51.net/js/2015/jquery-xlph-menu-codes/

具体代码如下：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://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>

希望本文所述对大家的jquery程序设计有所帮助。