HarmonyOS 通过子组件调用父组件方法修改父组件的值后，如何显示以及动态刷新父组件bindsheet标题栏的UI

父组件里用的bindsheet组件有个标题栏需要根据子组件滑动页面里的某个值，做到动态变化显示，

但是当前情况是日志打印可以看到刷新函数里的值获取到新的，父组件的文字却没有显示（只有按钮显示了，文字一直是空白），没有滑动子组件时:

父组件：

class TitleBuildParams {
  tileDisplayName: string = "";
}

const TAG = 'ParentView';

@Entry
@Component
struct Index {
  @State message: string = 'Hello World';
  @State parentSheetShow: boolean = false;
  @State mParentDisplayName: string = '';

  private updateDescription(formItem: string): void {
    this.mParentDisplayName = formItem;
    this.message = formItem;
    console.log(`onChange parent: ${this.mParentDisplayName}`);
  }

  @Builder
  bindSheetBuilder() {
    Column() {
      ChildComponent({
        mDisplayController: this.updateDescription
      })
    }
    .height(230)
  }


  @Builder
  titleAllBuilder() {
    this.titleBuilder({tileDisplayName: this.mParentDisplayName});
  }

  @Builder
  titleBuilder($$: TitleBuildParams) {
    Row() {
      Button() {
        Image($r('sys.media.ohos_ic_compnent_titlebar_back'))
          .width(24)
          .height(24)
          .fillColor($r('sys.color.ohos_id_color_titlebar_text'))
          .draggable(false)
      }
      .width(40)
      .height(40)
      .backgroundColor($r('sys.color.ohos_id_color_button_normal'))
      .onClick(() => {
        this.parentSheetShow = false;
      })

      Blank().width(8).visibility(Visibility.Hidden);

       //该处需要绑定显示动态刷新的值
      Text($$.tileDisplayName)
        .id(`${TAG}_Text_title`)
        .draggable(false)
        .fontColor($r('sys.color.ohos_id_color_text_primary'))
        .fontSize($r('sys.float.ohos_id_text_size_headline8'))
        .fontWeight(FontWeight.Bold)
        .lineHeight(30)
        .maxLines(1)
        .textOverflow({ overflow: TextOverflow.Ellipsis })
        .textAlign(TextAlign.Start)
    }
    .width('100%')
    .height('100%')
    .alignItems(VerticalAlign.Center)
    .justifyContent(FlexAlign.Start)
  }

  build() {
    RelativeContainer() {
      Text(this.message)
        .id('HelloWorld')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Top },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        })
      Button().width(30).height(30)
        .onClick((event) => {
          console.log("click button")
          this.parentSheetShow = true;
        })
      Stack().bindSheet($$this.parentSheetShow, this.bindSheetBuilder(), {
        title: this.titleAllBuilder(),
        width: 300,
        showClose: true,
        dragBar: false,
        blurStyle: BlurStyle.COMPONENT_ULTRA_THICK,
        backgroundColor: Color.Transparent,
        detents: [, 0],
        mode: SheetMode.EMBEDDED,
        onAppear: () => {
          console.log('Parent bindSheet onAppear');
        },
        onDisappear: () => {
          console.log(`Parent bindsheet onDisappear`);
          this.parentSheetShow = false;
        }
      })
    }
    .height('100%')
    .width('100%')
  }
}

子组件：

@Component
export default struct ChildComponent {
  private mDisplayController?: (formItem: string) => void = () => {};
  private mDisplayList : string[]= [];

  aboutToAppear(): void {
    this.mDisplayList = ["111", "222", "333"];
  }

  build() {
    Column() {
      Swiper() {
        ForEach(this.mDisplayList, (displayName: string, item: number) => {
          Column() {
            Text(displayName).fontSize(12).width(40).height(40)
          }.height(200).width('100%')
        }, (item: string, index: number): string => {
          return `${this.mDisplayList.length}${index}`;
        })
      }
      .onChange((index: number) => {
	//子组件有一个swiper切换index时，调用父组件的函数更新父组件的值
        if (this.mDisplayController != undefined && this.mDisplayList.length > index) {
          console.log(`onChange child: ${this.mDisplayList[index]}`);
          this.mDisplayController(this.mDisplayList[index]);
        }
      })
    }
  }
}