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<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>js scroll to the specified position navigation bar fixed top</title>
<style type="text/css">
body{height: 2500px; margin: 0; padding: 0;}
.banner{height: 250px; width: 100%; background: #e5e5e5;}
.bignav{width: 100%; background: #000;}
.nav{ background:#000; width: 1200px; margin: 0 auto; height: 45px;}
.nav a{display: block; width: 200px;float: left; color: #fff; text-decoration: none; text-align: center; line-height: 45px;}
</style>
</head>
<body>
<div class="banner">
</div>
<div class="bignav" id="bignav">
<div class="nav">
<a href="#">首页</a>
<a href="#">首页</a>
<a href="#">首页</a>
<a href="#">首页</a>
<a href="#">首页</a>
<a href="#">首页</a>
</div>
</div>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<p>Other content</p>
<script type="text/javascript">
window.onscroll=function(){
var topScroll =document.body.scrollTop;//Scroll distance, distance from the top
var bignav = document.getElementById("bignav");//Get the navigation bar id
if(topScroll > 250){ //Execute the following when the scroll distance is greater than 250px
bignav.style.position = 'fixed';
bignav.style.top = '0';
bignav.style.zIndex = '9999';
}else{//When the scroll distance is less than 250, execute the following content, which is to restore the navigation bar to its original state
bignav.style.position = 'static';
}
}
</script>
</body>
</html>
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