HarmonyOS 鸿蒙Next 如何实现一个 60:00 这种倒计时字符的效果

[@Entry](/user/Entry)
[@ComponentV2](/user/ComponentV2)
struct Index {
  [@Local](/user/Local) text: string = '120:00'
  startTime: number = 0
  duration = 2 * 60 

  aboutToAppear(): void {

  }

  build() {
    Column() {
      Text(this.text)
        .onClick(() => {
          this.start()
        })
    }
    .height('100%')
    .width('100%')
  }

  start() {
    this.startTime = Date.now()
    this.cycle(1000)
  }

  cycle(time: number) {
    setTimeout(() => {
      let time = Date.now()
      let duration = Math.floor((time - this.startTime) / 1000)
      let last = this.duration - duration
      let h = Math.floor(last / 60)
      let hh: string = h.toString()
      if (h < 10) {
        hh = '0' + hh
      }
      let m = last % 60
      let mm: string = m.toString()
      if (m < 10) {
        mm = '0' + mm
      }
      this.text = hh + ':' + mm
      this.cycle(1000 - (time - this.startTime) % 1000)
    }, time)
  }
}