HTML代码<section class="footer-popup">
<a class="side_btn top" id="back-to-top" href="javascript:;" title="返回顶部"
style="display: none;
width: 45px;
height: 45px;
background:url(/home/default/images/top_bg.png) no-repeat -1px -47px;">
</a>
</section>
js代码<script>
$(window).scroll(function () {
//获取滚动条距离顶部高度
var scrollTop = $(window).scrollTop();
//滚动条距离顶部高度为300的时候出现图标
scrollTop > 300 ? $("#back-to-top").fadeIn(200).css("display","block") : $("#back-to-top").fadeOut(200);
});
//返回顶部
$('#back-to-top').click(function (e) {
$('html,body').animate({ scrollTop:0});
});
</script>
<p style="text-align: center;">
<img src="https://www.f2er.com/res/2019/04-05/15/d0e9abaf79b0ee8b6d697c8dc60afdb2.jpg" title="js控制页面回到顶部" alt="js控制页面回到顶部">
