一款活动下拉式菜单的制作 ( jQuery & CSS )

时间：2010-08-22 来源：过期的风子

一款活动下拉式菜单的制作 ( jQuery & CSS )

之前介绍过几款导航的制作，反应比较好，今天再为大家介绍一款有子菜单的导航，也是利用 CSS & jQuery 功能制作的。

Step1. 创建HTML


<ul class="topnav">
    <li><a href="#">Home</a></li>
    <li>
    <a href="#">About Me</a>
    <ul class="subnav">
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    </ul>
    </li>
    <li>
    <a href="#">Portfolio</a>
    <ul class="subnav">
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    </ul>
    </li>
    <li><a href="#">Blog</a>
    <ul class="subnav">
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    <li><a href="#">Sub Nav Link</a></li>
    </ul>
    </li>
    <li><a href="#">Contact Me</a></li>
    <li><a href="#">Rss</a></li>
</ul>

Step2. 创建CSS

div.examples_body_wrap {
    width: 750px;
        margin: 50px auto 0 auto;
        clear: both;
}
div.examples_body_wrap h3 {
     color: #f9f66d;
     font-size: 130%;
         padding-bottom: 15px;
         margin-bottom: 15px;
         background: url(http://sunflowamedia.com/images/solid-line-news.gif) repeat-x bottom;
}
ul.topnav {
        width: 710px;
        padding: 0 0 200px 0;
        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; /*--Declare X and Y axis base for sub navigation--*/
 display: inline;
}
ul.topnav li a { 
        padding: 10px 5px;
        color: #fff;
        display: block;
        text-decoration: none;
        float: left;
}
ul.topnav li a:hover {
        background-color: #333;
        -moz-border-radius: 3px; /*--CSS3 Rounded Corners--*/
        -khtml-border-radius: 3px; /*--CSS3 Rounded Corners--*/
 -webkit-border-radius: 3px; /*--CSS3 Rounded Corners--*/
}
ul.topnav li span { /*--Drop down trigger styles--*/
        width: 17px;
        
        float: left;
        background: url(../images/subnav_btn.gif) no-repeat center top;
}
ul.topnav li span.subhover { /*--Hover effect for trigger--*/
    background-position: center bottom; cursor: pointer;
}   
ul.topnav li ul.subnav {
        width: 170px;
        position: absolute; /*--Important - Keeps subnav from affecting main navigation flow--*/
 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; /*--Create bevel effect--*/
        border-bottom: 1px solid #444; /*--Create bevel effect--*/
        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 { /*--Hover effect for subnav links--*/
 background-color: #222;
}

Step3. 插入jQuery和脚本包

$(document).ready(function(){   
  
    $("ul.subnav").parent().append(""); //Only shows drop down trigger when js is enabled (Adds empty span tag after ul.subnav*)   
  
    $("ul.topnav li span").mouseover(function() { //When trigger is clicked...   
  
        //Following events are applied to the subnav itself (moving subnav up and down)   
        $(this).parent().find("ul.subnav").slideDown('fast').show(); //Drop down the subnav on click   
  
        $(this).parent().hover(function() {   
        }, function(){   
            $(this).parent().find("ul.subnav").slideUp('slow'); //When the mouse hovers out of the subnav, move it back up   
        });   
  
        //Following events are applied to the trigger (Hover events for the trigger)   
        }).hover(function() {   
            $(this).addClass("subhover"); //On hover over, add class "subhover"   
        }, function(){  //On Hover Out   
            $(this).removeClass("subhover"); //On hover out, remove class "subhover"   
    });   
  
});

*红字 Mouseover 改成 click 就是点击后下拉!!!