<!DOCTYPE html><html lang="en"><head> ???<meta charset="UTF-8"> ???<title>Title</title> ???<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/animate.css@3.5.2/animate.min.css"> ???<style> ???????????#box{ ?????????width:200px; ?????????height: 200px; ?????????line-height: 200px; ?????????text-align: center; ?????????background-color: green; ?????????color: #fff; ?????????position: absolute; ?????????top: 500px; ?????} ???</style></head><body> ???<body style="height:2000px;"> ???<div id="box" class="animated infinite bounceOutLeft">春天来了</div> ???<script src="jquery.js"></script> ???<script> ???????$(function () { ???????????$(document).scroll(function () { ???????????????var scrollTop = $(this).scrollTop(); ???????????????console.log(scrollTop) ???????????????if(scrollTop>400){ ???????????????????$("#box").addClass("animated slideInDown") ???????????????} ???????????}) ???????}) ???</script> ???</body></body></html>animae.css动画 ??demo
原文地址：https://www.cnblogs.com/lxx7/p/9761598.html