<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.box {
width: 50px;;
margin: 100px auto;
}
.box li {
float: left;
width: 20px;
height: 20px;
background-color: pink;
margin: 15px;
background: url(OIP.jpg) no-repeat;
}
</style>
</head>
<body>
<div class="box">
<ul>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
<script>
//1.获取元素
var lis = document.querySelectorAll('li');
for(var i = 0 ; i<lis.length ;i++)
{
//让索引号乘以44 就是每个li的背景坐标 //index就是我们的y坐标
var index = i*44;
lis[i].style.backgroundPosition = '0 -'+index+'px';
console.log(lis[i].style.backgroundPosition);
}
</script>
</div>
</body>
</html>
