HarmonyOS中animateTo如何结束动画

@Entry 
@Component 
struct Page { 
  @State message: string = 'Hello World'; 
  @State opacityValue: number = 1 
  build() { 
    Row() { 
      Column() { 
        Text(this.message) 
          .fontSize(50) 
          .fontWeight(FontWeight.Bold) 
          .opacity(this.opacityValue) 
        Button('开始动画').onClick(() => { 
          animateTo({ duration: 5000, iterations: -1, playMode: PlayMode.AlternateReverse }, () => { 
            this.opacityValue = 0 
          }) 
        }) 
        Button('结束动画').onClick(() => { 
          animateTo({ 
            duration: 0, iterations: 1, onFinish: () => { 
              this.opacityValue = 1 
            } 
          }, () => { 
            this.opacityValue = 0.9 
          }) 
        }) 
      } 
      .width('100%') } 
    .height('100%') 
  } 
}