HarmonyOS TextTimer 计时器使用问题

count属性表示为倒计时初始值。（isCountDown为true时生效），单位为毫秒。最长不超过86400000毫秒（24小时）。 0<count<86400000时。示例如下：

@Entry
@Component
struct Index {
  textTimerController: TextTimerController = new TextTimerController()
  @State format: string = 'mm:ss.SS'
  build() {
    Column() {
      TextTimer({ isCountDown: true, count: 1200, controller: this.textTimerController })
        .format(this.format)
        .fontColor(Color.Black)
        .fontSize(50)
        .onTimer((utc: number, elapsedTime: number) => {
          console.info('textTimer notCountDown utc is：' + utc + ', elapsedTime: ' + elapsedTime)
        })
      Row() {
        Button("start").onClick(() => {
          this.textTimerController.start()
        })
        Button("pause").onClick(() => {
          this.textTimerController.pause()
        })
        Button("reset").onClick(() => {
          this.textTimerController.reset()
        })
      }
    }
  }
}