如何将导航栏（电池显示栏）进行沉浸，显示自己想要的View，当前默认顶部为白色

onWindowStageCreate(windowStage: window.WindowStage): void {  
  
  // Main window is created, set main page for this ability  
  hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');  
  windowStage.loadContent('pages/Index', (err, data) => {  
  if (err.code) {  
  hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');  
  return;  
}  
hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');  
let windowClass: window.Window | undefined = undefined;  
windowStage.getMainWindow((err: BusinessError, data) => {  
  let errCode: number = err.code;  
  if (errCode) {  
    console.error('Failed to obtain the main window. Cause: ' + JSON.stringify(err));  
    return;  
  }  
  windowClass = data;  
  console.info('Succeeded in obtaining the main window. Data: ' + JSON.stringify(data));  
  // 获取UIContext实例。  
  let uiContext: UIContext | null = null;  
  uiContext = windowClass.getUIContext();  
  let isLayoutFullScreen = true;  
  try {  
    windowClass.setWindowLayoutFullScreen(isLayoutFullScreen, (err: BusinessError) => {  
      const errCode: number = err.code;  
      if (errCode) {  
        console.error('Failed to set the window layout to full-screen mode. Cause:' + JSON.stringify(err));  
        return;  
      }  
      console.info('Succeeded in setting the window layout to full-screen mode.');  
    });  
  } catch (exception) {  
    console.error('Failed to set the window layout to full-screen mode. Cause:' + JSON.stringify(exception));  
  }  
})  
});  
}