鸿蒙（Arkts）定时器_arkts定时器

// 自定义计时器/倒计时组件
@Component
struct TimerComponent {
  @State counter: number = 0
  private changePerSec: number = -1
  private showInColor: Color = Color.Black
  private timerId: number = -1
 
  build() {
    Text(`${this.counter}sec`)
      .fontColor(this.showInColor)
      .fontSize(20)
      .margin(20)
  }
 
  aboutToAppear() {
    this.timerId = setInterval(() => {
      this.counter += this.changePerSec
    }, 1000)
  }
 
  aboutToDisappear() {
    if (this.timerId > 0) {
      clearTimeout(this.timerId)
      this.timerId = -1
    }
  }