HarmonyOS 自定义弹窗如何获取显示状态？

@CustomDialog  
struct CustomDialogExample {  
  cancel?: () => void  
  confirm?: () => void  
  controller: CustomDialogController  
  build() {  
    Column() {  
      Text('我是内容').fontSize(20).margin({ top: 10, bottom: 10 })  
      Flex({ justifyContent: FlexAlign.SpaceAround }) {  
        Button('cancel')  
          .onClick(() => {  
            this.controller.close()  
            if (this.cancel) {  
              this.cancel()  
            }  
          }).backgroundColor(0xffffff).fontColor(Color.Black)  
        Button('confirm')  
          .onClick(() => {  
            this.controller.close()  
            if (this.confirm) {  
              this.confirm()  
            }  
          }).backgroundColor(0xffffff).fontColor(Color.Red)  
      }.margin({ bottom: 10 })  
    }  
  }  
}  
@Entry  
@Component  
struct Index {  
  dialogController: CustomDialogController = new CustomDialogController({  
    builder: CustomDialogExample({  
      cancel: ()=> { this.onCancel() },  
      confirm: ()=> { this.onAccept() },  
    }),  
    autoCancel:true,  
    cancel: ()=> { this.onCancel()},  
  })  
  @State @Watch('dialogIsOpen') isOpen:boolean = false  
  dialogIsOpen(propName: string):void {  
    console.log('isOpen:',this.isOpen?1:0)  
  }  
  onCancel() {  
    this.isOpen = false  
    console.info('Callback when the first button is clicked')  
  }  
  onAccept() {  
    this.isOpen = false  
    console.info('Callback when the second button is clicked')  
  }  
  build() {  
    Column() {  
      Button('click me')  
        .onClick(() => {  
          this.dialogController.open()  
          this.isOpen = true  
        })  
    }.width('100%').margin({ top: 5 })  
  }  
}