如何将uitab条位置更改为顶部?

我有两个视图控制器,嵌入了标签栏控制器。它工作正常,但我想展示 tabbar 框架在视图顶部。我把镜框换到上面了,效果也不错。但问题在底部,它显示了一些 whitecolor 底部视图 塔巴 位置。

我的代码是

在 viewDidLoad

//Set selected item colour white on tab bar
UITabBar.appearance().tintColor = UIColor.white
//Set tab bar title position
UITabBarItem.appearance().titlePositionAdjustment = UIOffset(horizontal: 0, vertical: -12.5)
//Tab bar title font
UITabBarItem.appearance().setTitleTextAttributes([kCTFontAttributeName as NSAttributedStringKey: UIFont.boldSystemFont(ofSize: 15.0)], for: .normal)



override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    //Set tab bar frame on top position
    tabBar.frame = CGRect(x: 0, y: 0, width: tabBar.frame.size.width, height: tabBar.frame.size.height)
//        tabBar.isTranslucent = false
}

override func viewWillAppear(_ animated: Bool) {
    //Set navigation bar translucent
    navigationController?.navigationBar.isTranslucent = false
}