HarmonyOS 鸿蒙Next @State变量在闭包中修改能够引起UI更新，但是在实例方法中不行

HarmonyOS 鸿蒙Next @State变量在闭包中修改能够引起UI更新，但是在实例方法中不行

长按’长按按钮’触发 代码如下，长按按钮的onTouchDown事件在方法内改变@state变量无法引起UI刷新，但是在onTouchUp事件使用闭包能够引起UI更新

@Component
struct ContainerView {
  @BuilderParam child: () => void

  onTouchDown = ()=>{}
  onTouchUp = ()=>{}

  build() {
    Column() {
      Button('长按按钮')
        .onTouch((event)=>{
          if (event.type == TouchType.Down) {
            this.onTouchDown()
          } else if (event.type == TouchType.Up) {
            this.onTouchUp()
          }
        })
      this.child()
    }
  }
}

@Component
struct CustomBtn {
  build() {
    Button('自定义按钮')
  }
}

@Entry
@Component
struct MainPage {

  [@State](/user/State) title: string = '未点击'

  build() {
    Column() {
      ContainerView(
        {
          onTouchDown: this.onTouchDown,
          onTouchUp: ()=>{
            this.title = 'onTouchUp'
          }
        }
      ) {
        Text(this.title)
          .fontSize(200)

        CustomBtn()
          .onClick(()=>{
            console.log('已被点击')
          })
          .enabled(this.title == '未点击')
      }
    }
  }

  onTouchDown() {
    this.title = '已点击'
  }

  private onTouchUp() {
    this.title = '未点击'
  }
}