微信小程序实现单个或多个倒计时功能

// 单个倒计时-----wxml
<view class="countdown">
 <view class="item">
 倒计时：
 <view class="txt-time">{{txtTime.hou}}</view>:
 <view class="txt-time">{{txtTime.min}}</view>:
 <view class="txt-time">{{txtTime.sec}}</view>
 </view>
</view>

// 单个倒计时-----wxss
.countdown .item {
 display: flex;
 justify-content: center;
 align-items: center;
 height: 200rpx;
 width: 90%;
 margin: 0 5%;
 border-bottom: 2rpx solid #eee;
}

.countdown .item .txt-time {
 background-color: #6EBEC7;
 color: #fff;
 border-radius: 10rpx;
 font-size: 28rpx;
 margin: 0 4rpx;
 font-weight: bold;
 height: 42rpx;
 width: 66rpx;
 line-height: 42rpx;
 text-align: center;
}

// 单个倒计时-----js
Page({
 /**
 * 页面的初始数据
 */
 data: {
 endTime: "2020-08-22 18:30:00",//结束时间
 },

 //时间显示小于10的格式化函数
 timeFormat(param) {
 return param < 10 ? '0' + param : param;
 },
 //倒计时
 singleCountDown: function () {
 var that = this;
 var time = 0;
 var obj = {};
 var endTime = new Date(that.data.endTime.replace(/-/g, "/")).getTime();//结束时间时间戳
 var currentTime = new Date().getTime();//当前时间时间戳
 time = (endTime - currentTime) / 1000;
 // 如果活动未结束
 if (time > 0) {
 var hou = parseInt(time / (60 * 60));
 var min = parseInt(time % (60 * 60 * 24) % 3600 / 60);
 var sec = parseInt(time % (60 * 60 * 24) % 3600 % 60);
 obj = {
 hou: that.timeFormat(hou),
 min: that.timeFormat(min),
 sec: that.timeFormat(sec)
 }
 } else { //活动已结束
 obj = {
 hou: "00",
 min: "00",
 sec: "00"
 }
 clearTimeout(that.data.timeIntervalSingle); //清除定时器
 }
 var timeIntervalSingle = setTimeout(that.singleCountDown, 1000);
 that.setData({
 timeIntervalSingle,
 txtTime: obj,
 })
 },

 /**
 * 生命周期函数--监听页面加载
 */
 onLoad: function (options) {
 this.singleCountDown();//页面加载时就启动定时器
 },
})

// 多个倒计时显示-----wxml
<view class="countdown">
 <block wx:for="{{timeList}}" wx:key="index">
 <view class="item">
 {{item.title}}：
 <view class="txt-time">{{item.time.hou}}</view>:
 <view class="txt-time">{{item.time.min}}</view>:
 <view class="txt-time">{{item.time.sec}}</view>
 </view>
 </block>
</view>

// 多个倒计时显示-----wxml
Page({
 /**
 * 页面的初始数据
 */
 data: {
 timeList: [{//时间数组
 title: "a倒计时",
 endTime: "2020-08-23 18:00:00",
 }, {
 title: "b倒计时",
 endTime: "2020-08-25 20:00:00",
 }, {
 title: "c倒计时",
 endTime: "2020-08-21 20:00:00",
 }],
 },

 //时间显示小于10的前面补0方法
 timeFormat(param) {
 return param < 10 ? '0' + param : param;
 },
 //多个倒计时函数
 severalCountDown: function () {
 var that = this;
 var time = 0;
 var obj = {};
 var timeList = that.data.timeList;
 //遍历数组，计算每个item的倒计时秒数
 timeList.forEach(function (item) {
 var endTime = new Date(item.endTime.replace(/-/g, "/")).getTime();//结束时间时间戳
 var currentTime = new Date().getTime();//当前时间时间戳
 time = (endTime - currentTime) / 1000;
 // 如果活动未结束
 if (time > 0) {
 var hou = parseInt(time / (60 * 60));
 var min = parseInt(time % (60 * 60 * 24) % 3600 / 60);
 var sec = parseInt(time % (60 * 60 * 24) % 3600 % 60);
 obj = {
  hou: that.timeFormat(hou),
  min: that.timeFormat(min),
  sec: that.timeFormat(sec)
 }
 } else { //活动已结束
 obj = {
  hou: "00",
  min: "00",
  sec: "00"
 }
 clearTimeout(that.data.timeIntervalSeveral); //清除定时器
 }
 item.time = obj;
 })
 var timeIntervalSeveral = setTimeout(that.severalCountDown, 1000);
 that.setData({
 timeIntervalSeveral,
 timeList,
 })
 },

 /**
 * 生命周期函数--监听页面加载
 */
 onLoad: function (options) {
 this.severalCountDown();//多个定时器
 },
})