这个问题课可以查看窗口沉浸，我建议使用setWindowLayoutFullScreen()来实现应用全屏，并且弃用ignoreLayoutSafeArea()和expandSafeArea，这两个使用起来再多层组件嵌套的时候很容易混乱，不容易理清。可以查看以下代码：

onWindowStageCreate(windowStage: window.WindowStage) {
    // Main window is created, set main page for this ability
    Logger.info(TAG, 'Ability onWindowStageCreate');

    windowStage.loadContent('pages/Index', (err, data) => {
      if (err.code) {
        Logger.error(TAG, `Failed to load the content. Cause: ${JSON.stringify(err) ?? ''}`);
        return;
      }
      Logger.info(TAG, `Succeeded in loading the content. Data: ${JSON.stringify(data) ?? ''}`);
    });

    try {
      windowStage.getMainWindow((err, data) => {
        if (err.code) {
          Logger.error(TAG, `getMainWindow failed, code=${err.code}, msg=${err.message}`);
          return;
        }
        data.setWindowLayoutFullScreen(true).then(() => {
          Logger.info(TAG, `Succeeded to change full-screen state: ${true}.`);
        }).catch((err: Error) => {
          Logger.error(TAG, `Failed to change full-screen state. Cause message: ${JSON.stringify(err)}`);
        });
        data.setWindowBackgroundColor(Constants.BACKGROUND_COLOR)
      })
    } catch (error) {
      Logger.error(TAG, `Ability onWindowStageCreate, error=${JSON.stringify(error)}`);
    }
  }

应用设置全屏后，所有界面都会延伸到状态栏和导航栏，使窗口沉浸，如果想规避的话可以手动在顶部和底部添加空白组件，设置topRect和bottomRect，获取逻辑如下：

  /**
   * 初始化窗口属性
   * 获取窗口的初始尺寸、安全区信息等
   * 注意：断点由媒体查询系统统一管理，此处不设置断点
   * @param windowClass 窗口实例
   */
  private initializeWindowProperties(): void {
    const windowClass = this.mainWindowClass
    try {
      // 获取系统状态栏避让区域
      const systemAvoidArea = windowClass!.getWindowAvoidArea(window.AvoidAreaType.TYPE_SYSTEM);
      this.windowProperties.topRectPx = systemAvoidArea.topRect.height
      this.windowProperties.topRect = this.uiContext!.px2vp(systemAvoidArea.topRect.height);
      Logger.info(TAG, `顶部安全区高度: ${this.windowProperties.topRectPx}px`);
      Logger.info(TAG, `顶部安全区高度: ${this.windowProperties.topRect}vp`);

      // 获取导航栏避让区域
      const navAvoidArea = windowClass!.getWindowAvoidArea(window.AvoidAreaType.TYPE_NAVIGATION_INDICATOR);
      this.windowProperties.bottomRectPx = navAvoidArea.bottomRect.height
      this.windowProperties.bottomRect = this.uiContext!.px2vp(navAvoidArea.bottomRect.height);
      Logger.info(TAG, `底部安全区高度: ${this.windowProperties.bottomRectPx}px`);
      Logger.info(TAG, `底部安全区高度: ${this.windowProperties.bottomRect}vp`);

      // 获取窗口尺寸
      const windowSize = windowClass!.getWindowProperties().windowRect;
      this.windowProperties.winWidthPx = windowSize.width
      this.windowProperties.winHeightPx = windowSize.height
      this.windowProperties.winWidth = this.uiContext!.px2vp(windowSize.width);
      this.windowProperties.winHeight = this.uiContext!.px2vp(windowSize.height);
      Logger.info(TAG, `窗口尺寸: ${this.windowProperties.winWidth}x${this.windowProperties.winHeight}vp`);
      Logger.info(TAG, `窗口尺寸: ${this.windowProperties.winWidthPx}x${this.windowProperties.winHeightPx}px`);

      // 获取窗口装饰高度（如果支持）
      if (canIUse('SystemCapability.Window.SessionManager')) {
        const height = windowClass!.getWindowDecorHeight();
        this.windowProperties.decorHeightPx = height
        this.windowProperties.decorHeight = this.uiContext!.px2vp(height);
        Logger.info(TAG, `窗口装饰高度: ${this.windowProperties.decorHeight}vp`);
        Logger.info(TAG, `窗口装饰高度: ${this.windowProperties.decorHeightPx}px`);
      }
    } catch (error) {
      Logger.error(TAG, `初始化窗口属性失败: ${error.message}`);
    }
  }

获取避让高度后可以在UI中使用AppStorage使用。