60分钟倒计时

count就是需要倒计时的时间，如60分钟，但是单位是秒，
所以60分钟转化成秒是 60*60 = 3600

data(){
  return{
    count: 3600
  }
}

timer = setInterval(() => {
    this.hours = this.count/3600 < 10 ? ('0' + parseInt(this.count/3600)) : parseInt(this.count/3600);
    this.minutes = (this.count-this.hours*3600)/60 < 10 ? ('0' + parseInt((this.count-this.hours*3600)/60)) : parseInt((this.count-this.hours*3600)/60);
    this.seconds = (this.count%60) < 10 ? ('0' + this.count%60) : this.count%60;
    this.count--;
}, 1000)