微信小程序 短信验证码登录 倒计时 setInterval

需求：输入手机号 -> 点击获取验证码 -> 进入60s倒计时

  data: { 
    seconds: 0, // 读秒
    timer: '' // 计时器
  }, 

      let that = this
      // 开始倒计时
      that.setData({ 
        seconds: 60,
        timer: setInterval(function(){
          let seconds = that.data.seconds
          that.setData({ seconds: seconds - 1 })
          if (that.data.seconds == 0) {
            // 读秒结束 清空计时器
            clearInterval(that.data.timer)
          }
        }, 1000)
      })