最近在幫同學寫一個部落格，由于他需要的欄目比較多，是以首頁需要三級下拉菜單，從網上找一個，但是不可以直接用!由于前台沒有寫的太好，是以一些css代碼沒有看懂，是以我就分析了一下别人的代碼，然後用到了自己的網站上，下面是我最後實作的效果。
下面分析一下我找的代碼：
實作效果如下:
代碼以及注釋如下，一些标簽的意思已在注釋上标明:
主要思想：就是改變ul的display屬性
一開始ul的display屬性是none不顯示，當a标簽hover的時候，改變ul的display屬性使它成為display:block
也就是display:none ------>display:block的變化
其中加入了一些過渡的屬性，要不直接放在一級菜單上，二級菜單直接出來，看着有點不舒服，是以加了一點過渡屬性
-webkit-transition: all 1s; /*Firefox4*/
-moz-transition: all 1s; /*Safari and Chrome*/
-o-transition: all 1s; /* Opera*/
transition: all 1s;
<!DOCTYPE html>
<html >
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
nav {
margin: 100px auto;
text-align: center;
}
nav ul ul {
display: none; /*該元素不會顯示*/
}
nav ul li:hover > ul { /* > 子菜單選擇器 滑鼠在li上的時候 改變子ul的display屬性*/
display: block;
}
nav ul {
background: #efefef;
background: linear-gradient(top, #efefef 0%, #bbbbbb 100%); /*背景的一些設定 漸變*/
background: -moz-linear-gradient(top, #efefef 0%, #bbbbbb 100%);
background: -webkit-linear-gradient(top, #efefef 0%,#bbbbbb 100%);
box-shadow: 0px 0px 9px rgba(0,0,0,0.15); */
padding: 0 20px; */
border-radius: 10px; /*圓角邊框*/
list-style: none; /*所有的清單屬性*/
position: relative; /*相對定位ul的位置*/
display: inline-table; /*内斂表格*/
}
nav ul:after { /* css after選擇器 */
content: "";
clear: both;
display: block;
}
nav ul li {
/*
transition 屬性是一個簡寫屬性，用于設定四個過渡屬性：
transition-property
transition-duration
transition-timing-function
transition-delay
transition前面的參數是相容浏覽器用的
*/
-webkit-transition: all 1s; /*Firefox4*/
-moz-transition: all 1s; /*Safari and Chrome*/
-o-transition: all 1s; /* Opera*/
transition: all 1s;
float: left; /*使豎向菜單變為橫向菜單*/
}
nav ul li:hover {
background: #4b545f;
background: -webkit-linear-gradient(#4f5964 0%, #5f6975 40%);
background: -o-linear-gradient(#4f5964 0%, #5f6975 40%);
background: linear-gradient(#4f5964 0%, #5f6975 40%);
}
nav ul li:hover a {
color: #fff;
}
nav ul li a {
display: block; /*使a标簽變成塊狀*/
padding: 25px 40px; /*a标簽左右的距離*/
color: #757575;
text-decoration: none; /*文本的屬性*/
}
nav ul ul {
background: #5f6975;
border-radius: 0px; padding: 0;
position: absolute; /*定義子ul的位置*/
top: 100%;
}
nav ul ul li {
float: none; /*清楚子ul裡面li标簽的浮動*/
border-top: 1px solid #6b727c; /*下拉菜單中的分割線*/
border-bottom: 1px solid #575f6a;
position: relative;
}
nav ul ul li a {
padding: 15px 40px;
color: #fff;
}
nav ul ul li a:hover {
background: #4b545f;
}
nav ul ul ul{
position: absolute; left: 100%; top:0;
}
</style>
</head>
<body>
<nav>
<ul>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Home</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Tutorials</a>
<ul>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Photoshop</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Illustrator</a>
<ul>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >HTML</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >CSS</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >HTML</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >CSS</a></li>
</ul>
</li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Web Design</a>
<ul>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >HTML</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >CSS</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Articles</a>
<ul>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Web Design</a></li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >User Experience</a></li>
</ul>
</li>
<li><a href="#" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" target="_blank" rel="external nofollow" >Inspiration</a></li>
</ul>
</nav>
</body>
</html>