<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>Document</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
img{
border:0;
}
ol, ul ,li{list-style: none;}
body > div div{
width:800px;
height:400px;
margin: 40px auto;
border:1px
}
.nav a {display:inline-block;margin:0 30px;padding: 0 20px;color:
.nav {width:100%;position: fixed;top:0;}
.nav nav {margin: 0 auto;width:1200px;text-align: center;height:50px;background-color: black;}
.nav .active {background-color: red;transition: all .2s;}
.nav a:hover{background-color: red;}
</style>
</head>
<body>
<div class="nav">
<nav>
<a href="#one" class="active">第一</a>
<a href="#two">第二</a>
<a href="#three">第三</a>
<a href="#four">第四</a>
</nav>
</div>
<div id="topel">
<div id="one"></div>
<div id="two"></div>
<div id="three"></div>
<div id="four"></div>
<div></div>
<div></div>
<div></div>
<div></div>
</div>
<script src="http://code.jquery.com/jquery-1.8.0.min.js"></script>
<script type="text/javascript">
$(function () {
$('.nav a').on('click',function () {
$(this).addClass('active').siblings('a').removeClass('active');
});
$(window).scroll(function(event) {
function offset (x,m,n,j,num1,num2) {
function addes (y) {$(y).addClass('active').siblings('a').removeClass('active');}
if ( x == 0) {addes('.nav a:eq(0)');}
if (x >= m - num1 && x <= m + num2) {addes('.nav a:eq(1)'); }
if (x >= n - num1 && x <= n + num2) {addes('.nav a:eq(2)'); }
if (x >= j - num1 && x <= j + num2) {addes('.nav a:eq(3)'); }
}
offset($(this).scrollTop(),two.offsetTop,three.offsetTop,four.offsetTop,90,40)
});
console.log($('#two').offset().top);//等價console.log(two.offsetTop);
console.log($(window).scrollTop());
console.log(document.documentElement.scrollTop)
})
</script>
</body>
</html>
複製程式碼