使用 CSS 3 实现简单二级菜单

IE 9+

 

运用 CSS 3 属性：

transform: rotate(180deg);  /*旋转 180 度*/
transition: top ease 1s;   /*过渡效果*/
box-shadow: 0 6px 6px rgba(0,0,0,0.2);  /*阴影*/
border-radius:0 0 6px 6px;  /*圆角*/
background:rgba(0,0,0,0.8);  /*背景透明*/

 

效果图：

 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>使用 CSS 3 实现简单二级菜单</title>
    <style type="text/css">
        *{margin: 0;padding: 0;}
        li{list-style: none}
        *, *:after, *:before {
            -webkit-box-sizing: border-box;
            box-sizing: border-box;
        }
        *{zoom:1}
        /*清除浮动*/
        .clearfix:after {
            content: " ";
            display: block;
            clear: both;
            height: 0;
        }
        .clearfix {
            zoom: 1;
        }
        .nav{
            margin: 100px;
            background: #000;
            position: relative;
            z-index: 999;
            float: left;
        }
        .nav a{
            display: block;
            text-decoration: none;
            color: #FFF;
            background: #000;
        }
        .nav>li{
            display: inline-block;
            float: left;
            position: relative;
            height: 40px;
            z-index: 999;
        }
        .nav>li>.caret{
            width: 0;
            height: 0;
            display: inline-block;
            border:5px solid transparent;
            border-top: 0;
            border-bottom-color: #FFF;
            content: " ";
            position: absolute;
            top: 20px;
            right: 5px;
            z-index:3 ;
        }
        .nav>li>.caret.down{
            -webkit-transform: rotate(180deg);
            transform: rotate(180deg);  /*旋转*/
            /*
            border:5px solid transparent;
            border-bottom: 0;
            border-top-color: #FFF;
            */
        }
        .nav>li>a{
            position: relative;
            z-index: 2;
            padding: 10px 20px;
        }
        .nav ul{
            position: absolute;
            top:0;
            -webkit-transition: top ease 1s;
            transition: top ease 1s;   /*过渡效果*/
            z-index: 1;
            border: 1px solid #999;
            border-top: 0;
            width: 100%;
            height: 0;
            -webkit-box-shadow: 0 6px 6px rgba(0,0,0,0.2);
            box-shadow: 0 6px 6px rgba(0,0,0,0.2);  /*阴影*/
            border-radius:0 0 6px 6px;  /*圆角*/
            overflow: hidden;
        }
        .nav ul.show{
            top:40px;
            height: auto;
        }
        .nav ul>li{
            border-bottom: 1px solid #999;
        }
        .nav ul>li:last-child{ border: 0; }
        .nav ul>li>a{
            padding: 10px 0;
            text-align: center;
            background:rgba(0,0,0,0.8);  /*背景透明*/
        }
        .nav ul>li>a:hover{
            background:rgba(0,0,0,0.6);
        }
    </style>
    <script type="text/javascript" src="https://cdn.bootcss.com/jquery/1.12.4/jquery.min.js"></script>
    <script type="text/javascript">
        $(function () {
            $(".nav>li").hover(function () {
                $(this).children("ul").toggleClass("show");
                $(this).children(".caret").toggleClass("down");
            });
            $(".nav>li").each(function () {
                if($(this).find("ul").length>0){
                    $(this).append("<span class='caret'></span>");
                }
            });
        });
    </script>
</head>
<body>
    <ul class="nav">
        <li><a href="#">一级菜单</a></li>
        <li>
            <a href="#">一级菜单</a>
            <ul>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
            </ul>
        </li>
        <li>
            <a href="#">一级菜单</a>
            <ul>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
            </ul>
        </li>
        <li>
            <a href="#">一级菜单</a>
            <ul>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
            </ul>
        </li>
        <li>
            <a href="#">一级菜单</a>
            <ul>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
            </ul>
        </li>
        <li>
            <a href="#">一级菜单</a>
            <ul>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
                <li><a href="#">二级菜单</a></li>
            </ul>
        </li>
    </ul>
</body>
</html>

 

posted @ 2017-11-18 17:23  linyongqin  阅读(250)  评论(0)  编辑  收藏  举报