編程練習
運用css和jQuery，實現(xiàn)導(dǎo)航菜單在右側(cè)絕對定位顯示，并且可以在滾動時根據(jù)滾動條的位置自動設(shè)置導(dǎo)航菜單的焦點。
溫馨提示 : 完成任務(wù)后，請驗證是否與實踐描述效果一致，如一致，恭喜您，你已經(jīng)掌握此技能，否則，請重復(fù)學(xué)習此節(jié)內(nèi)容。
任務(wù)
一、靜態(tài)網(wǎng)頁的實現(xiàn)
1.運用CSS，讓導(dǎo)航菜單在右側(cè)絕對定位顯示。
2.運用錨點，實現(xiàn)導(dǎo)航定位。
提示: 使用position屬性。
二、jQuery實現(xiàn)定位導(dǎo)航特效
1.滾動條發(fā)生滾動時，要獲取相應(yīng)的值。
提示:先要獲取到相應(yīng)的scrollTop()、導(dǎo)航和當前所在的樓層。
2.實現(xiàn)讓導(dǎo)航菜單在滾動條滾動的時候自動設(shè)置焦點
提示：這里遍歷時需要對滾動條位置和每個元素位置做一個判斷，并把相應(yīng)的元素id值賦予currentId
3. 給相應(yīng)樓層的 a 設(shè)置current，取消其他鏈接的current
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<title>地狗購物網(wǎng)——網(wǎng)頁定位導(dǎo)航效果</title>
<style>
* {
margin: 0;
padding: 0;
}
body {
font-size: 12px;
line-height: 1.7;
}
li {
list-style: none;
}
#content {
width: 800px;
margin: 0 auto;
padding: 20px;
}
#content h1 {
color: #0088bb;
}
#content .item {
padding: 20px;
margin-bottom: 20px;
border: 1px dotted #0088bb;
}
#content .item h2 {
font-size: 16px;
font-weight: bold;
border-bottom: 2px solid #0088bb;
margin-bottom: 10px;
}
#content .item li {
display: inline;
margin-right: 10px;
}
#content .item li a img {
width: 230px;
height: 230px;
border: none;
}
/*請補充此處代碼，讓導(dǎo)航菜單在右側(cè)絕對定位顯示*/
}
#menu ul li a {
display: block;
margin: 5px 0;
font-size: 14px;
font-weight: bold;
color: #333;
width: 80px;
height: 50px;
line-height: 50px;
text-decoration: none;
text-align: center;
}
#menu ul li a:hover,
#menu ul li a.current {
color: #fff;
background: #0088bb;
}
/*ie6 hack*/
* html, * html body {
background-image: url(about:blank);
background-attachment: fixed;
}
* html #menu {
/*position: fixed;*/
position: absolute;
top: expression(((e=document.documentElement.scrollTop)?e:document.body.scrollTop)+100+'px');
}
</style>
<script src="http://libs.baidu.com/jquery/1.10.2/jquery.js"></script>
<script>
//滾動條發(fā)生滾動時，要獲取相應(yīng)的值。
//請補充此處代碼，讓導(dǎo)航菜單實現(xiàn)在滾動條滾動的時候自動設(shè)置焦點
//給相應(yīng)樓層的a 設(shè)置 current，取消其他鏈接的current
</script>
</head>
<body>
<div id="menu">
<ul>
<!--運用錨點，實現(xiàn)導(dǎo)航定位。-->
<li><a href="#" class="current">1F 男裝</a></li>
<li><a href="#">2F 女裝</a></li>
<li><a href="#">3F 美妝</a></li>
<li><a href="#">4F 數(shù)碼</a></li>
<li><a href="#">5F 母嬰</a></li>
</ul>
</div>
<div id="content">
<h1>地狗購物網(wǎng)</h1>
<div id="item1" class="item">
<h2>1F 男裝</h2>
<ul>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//53660fce0001111903990422.jpg" alt=""/></a></li>
</ul>
</div>
<div id="item2" class="item">
<h2>2F 女裝</h2>
<ul>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//5366104c0001e5c403990422.jpg" alt=""/></a></li>
</ul>
</div>
<div id="item3" class="item">
<h2>3F 美妝</h2>
<ul>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610820001cf5b03990422.jpg" alt=""/></a></li>
</ul>
</div>
<div id="item4" class="item">
<h2>4F 數(shù)碼</h2>
<ul>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610ac00012df703990422.jpg" alt=""/></a></li>
</ul>
</div>
<div id="item5" class="item">
<h2>5F 母嬰</h2>
<ul>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
<li><a href="#"><img src="http://img1.sycdn.imooc.com//536610cd0001f34603990422.jpg" alt=""/></a></li>
</ul>
</div>
</div>
</body>
</html>
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