返回顶部案例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
body{
height: 5000px;
background-image: linear-gradient(to bottom,blue,green,yellow);
}
.backtotop {
width: 60px;
height: 60px;
background-color: rgba(255,255,255.6);
position: fixed;
bottom: 100px;
right: 100px;
cursor: pointer;
}
</style>
</head>
<body>
<div class="backtotop" id="backtotop"> 返回顶部 </div>
<script>
var backtotop = document.getElementById('backtotop')
var timer
backtotop.onclick = function(){
clearInterval(timer)
timer = setInterval(function(){
document.documentElement.scrollTop -= 200
if(document.documentElement.scrollTop <= 0 ){
clearInterval(timer)
}
},20)
}
</script>
</body>
</html>
