uniapp微信小程序实现一个页面多个倒计时

<view class="group-list" v-for="item in message" :key="item.productid">
 <view class="group-img" @click="navto">
 <image :src="item.productpicture"></image>
 </view>
 <view class="group-info">
 <view class="product-name">{{ item.productname }}</view>
 <view class="product-price">
  <text class="discounts">￥{{ item.productcurrentprice }}</text>
  <text class="original">￥{{ item.productmarketprice }}</text>
 </view>
 <view class="group-partner">
  <scroll-view scroll-x>
  <view class="user-img">
   <view v-for="(single, index) in item.avatarlist" :key="index">
   <image :src="single"></image>
   </view>
   <view v-for="i in item.stillmissingnumber" :key="i">
   <image src="../../static/ssll-img/more.png"></image>
   </view>
  </view>
  </scroll-view>
  <button open-type="share">邀请好友</button>
 </view>
 <view class="clock">
  <text>拼团剩余：</text>
  <!-- 绑定倒计时 -->
  <text>{{ item.end_time1 }}</text> 
 </view>
 </view>
</view>

export default {
 data() {
  return {
  timedata: '',  //存放每条数据的处理好的倒计时
  timer: '',  //用来清除定时器
  message: []  //接口请求返回的数据
  }
 },
 onunload(){  //卸载页面清除定时器
   clearinterval(this.timer) 
 },
 methods: {
  gettimelist(){ 
    let that = this
    that.message.foreach((item) =>{
     var nowdate = new date().gettime()  //获取当前时间毫秒数
     var time = item.productexpiredtime.replace(new regexp("-", "gm"), "/") //ios不能识别日期格式中的 "-" ； .productexpiredtime是接口返回的名称
     var timesp = time.split('.')[0]  //此处是因为我们接口返回的时间格式是这样："2019-12-31 11:00:00.0"
     var enddate = new date(timesp).gettime()  //处理好格式之后获取结束时间的毫秒数
     var totaltime = enddate - nowdate   //获取时间差
     that.totaltime(totaltime)  //这是下面封装的方法，将毫秒数处理成"xx时xx分xx秒"
     item.end_time1 = that.timedata //处理好的单个时间安排到item上（重要）
    })
    this.message = that.message  //全部处理好的数据重新赋值
  },
  
  totaltime(a){  //计算单个剩余时间
   let totaltime = a
    let that = this
     var h, m, s, d
     function test(num) {
       if (num < 10) {
         num = "0" + num  
       }
       return num
     }
     
    if (totaltime > 0) {
      d = math.floor(totaltime / 1000 / 60 / 60 / 24) * 24
      h = math.floor(totaltime / 1000 / 60 / 60 % 24)
      m = math.floor(totaltime / 1000 / 60 % 60)
      s = math.floor(totaltime / 1000 % 60)
      //获取时分秒
      h = d + h
      h = test(h)
      m = test(m)
      s = test(s)
      
      this.timedata =`${h}时 : ${m}分 : ${s}秒`  // 每个时间的显示格式
     
    } else {
      
      this.timedata = `00 : 00 : 00` 
     
    }
  },
  //以下请求此页面需要的数据
  getusergrouplist(接口参数) {
  this.$ajax({
   url: 'xxx/xxx/xxxxxx',
   data: {接口参数},
   success: res => {
   var that = this
   let data = res.data.groups
   if (data.length === 0) {
    this.$api.msg('暂时您还没有参团信息！')
    settimeout (function() {
    uni.navigateback({  //返回上一页
      delta: 1
    })
    },1500)
   } else {
    this.message = [...that.message, ...res.data.groups]  //合并
    //数据返回成功之后再调计时器，防止异步
    //that.gettimelist()
    var timer = setinterval(function () {
      that.gettimelist()
    }, 1000)
    this.timer = timer
   }
   }
  }
}