js的日期倒计时在日常项目中还是比较常用的,活动、拼团功能最为常见;
先分析最要是处理好日期函数,然后一个页面上有多个倒计时情况下的方法;
来,先看下 拼多多 的拼单倒计时的效果:
那么,先上个代码吧:
案例效果:
<html> <head> <meta charset="UTF-8"> <title>js拼团日期倒计时</title> <style> .mytime{ line-height: 40px; width: 300px; margin: 0 auto;} </style> </head > <body> <div class="mytime jsTime" data-time="2019-03-28 16:58:00">时间1</div> <div class="mytime jsTime" data-time="2019-03-29 14:00:02">时间2</div> <div class="mytime jsTime" data-time="2019-03-30 18:01:31">时间3</div> <div class="mytime jsTime" data-time="2019-03-31 05:05:15">时间4</div> <div class="mytime jsTime" data-time="2019-04-01 09:01:43">时间5</div> </body> </html>
<script> const countdown = { domList : document.querySelectorAll('.jsTime'), formatNumber(n){ // return n.toString().padStart(2, '0'); // 用padStart方法要注意兼容问题 n = n.toString(); return n[1] ? n : '0' + n; }, setTime(dom){ //获取设置的时间 如:2019-3-28 14:00:00 const leftTime = new Date(dom.getAttribute('data-time')) - new Date(); if (leftTime >= 0) { const d = Math.floor(leftTime / 1000 / 60 / 60 / 24); const h = Math.floor(leftTime / 1000 / 60 / 60 % 24); const m = Math.floor(leftTime / 1000 / 60 % 60); const s = Math.floor(leftTime / 1000 % 60); dom.innerHTML = `剩余${ d > 0 ? d + '天' : '' }${ [h, m, s].map(this.formatNumber).join(':') }`; } else { clearInterval(dom.$timer); dom.innerHTML = '拼团已结束'; } }, start(){ this.domList.forEach((dom) => { this.setTime(dom); dom.$timer = setInterval(() => { this.setTime(dom); }, 1e3); }); }, }; countdown.start(); </script>