HarmonyOS 如何获取底部导航栏高度？

获取底部导航条高度，可以参考如下demo:

aboutToAppear(): void {
  window.getLastWindow(getContext(this), (error, topWindow) => {
  if (topWindow) {
    let area = topWindow.getWindowAvoidArea(window.AvoidAreaType.TYPE_SYSTEM);
    let areaBottom = topWindow.getWindowAvoidArea(window.AvoidAreaType.TYPE_NAVIGATION_INDICATOR);
    //注意：返回的是px值，如果要用vp值需要转换
    this.bottomRectHeight = px2vp(areaBottom.bottomRect.height);
    this.statusBarHeight = px2vp(area.topRect.height);
    console.log('this.statusBarHeight' + this.statusBarHeight)
    console.log('this.bottomRectHeight' + this.bottomRectHeight)
  }
});
}