实现滑动页面导航栏固定在网页顶部
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>导航栏固定在网页顶部</title>
<style type="text/css">
*{ margin: 0; padding: 0; }
.header-wrap{ width: 100%; }
.header-hd{ width: 980px; height: 150px; margin: 0 auto; background-color: #ccc; }
.header-bd{ width: 980px; height: 40px; margin: 0 auto; background-color: red; }
.fixed{ position: fixed; width: 100%; }
.fixed .header-hd{ display: none; }
</style>
<script type="text/javascript">
window.onload=function(){
function adsorption(){
var headerWrap=document.getElementById('header-wrap');
var scrollTop=0;
window.onscroll=function(){
scrollTop=document.body.scrollTop||document.documentElement.scrollTop;
if(scrollTop>100){
headerWrap.className='fixed';
}else{
headerWrap.className='header-wrap';
}
}
}
adsorption();
}
</script>
</head>
<body style="height:4000px;">
<div id="header-wrap" class="header-wrap">
<div class="header-hd"></div>
<div class="header-bd"></div>
</div>
</body>
</html>
