Ios 在弹出vc时在选项卡栏下显示的UITabBar上添加子视图

我有一个简单的选项卡栏项目，我在选项卡栏上添加了一个图像，一开始看起来不错

当pushed=true时，第二个视图从HidesBottomBar的FirstViewController中推送。然后，我隐藏了按钮，该按钮是出于正当理由添加到视图上的，而不是作为子视图添加到选项卡栏上的

一切正常，直到我按下后退按钮，当我取消隐藏视图（或重新创建它）时，显示在选项卡栏下

我应该将showButton（）方法放在哪个方法中，以便它再次显示在选项卡栏上

有什么建议吗

CustomTabBarController.swift

class CustomTabBarController: UITabBarController {

    var bigButton: UIImageView!

    func addCenterButton() {
      let image = UIImage(named: "bigButtonBackground")
      bigButton = UIImageView(image: image)
      bigButton.frame = CGRectMake(0.0, 0.0, image!.size.width, image!.size.height);
      bigButton.autoresizingMask = .FlexibleRightMargin | .FlexibleLeftMargin | .FlexibleBottomMargin | .FlexibleTopMargin
      let heightDifference = image!.size.height - tabBar.frame.size.height
      var center = tabBar.center
      center.y = center.y - heightDifference/2.0
      bigButton.center = center

      view.addSubview(bigButton)   
     }

     func hideButton() {
       bigButton.hidden = true   
     }

     func showButton() {
       bigButton.hidden = false
       view.bringSubviewToFront(bigButton)  
     }
}

class FirstViewController: UIViewController {

  override func viewDidLoad() {
    super.viewDidLoad()
    (tabBarController as! CustomTabBarController).addCenterButton()
  }

  override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    (tabBarController as! CustomTabBarController).showButton()
  }

  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    let viewController = segue.destinationViewController as! UIViewController

    (tabBarController as! CustomTabBarController).hideButton()
    viewController.hidesBottomBarWhenPushed = true
  }
}

FirstViewController.swift

class CustomTabBarController: UITabBarController {

    var bigButton: UIImageView!

    func addCenterButton() {
      let image = UIImage(named: "bigButtonBackground")
      bigButton = UIImageView(image: image)
      bigButton.frame = CGRectMake(0.0, 0.0, image!.size.width, image!.size.height);
      bigButton.autoresizingMask = .FlexibleRightMargin | .FlexibleLeftMargin | .FlexibleBottomMargin | .FlexibleTopMargin
      let heightDifference = image!.size.height - tabBar.frame.size.height
      var center = tabBar.center
      center.y = center.y - heightDifference/2.0
      bigButton.center = center

      view.addSubview(bigButton)   
     }

     func hideButton() {
       bigButton.hidden = true   
     }

     func showButton() {
       bigButton.hidden = false
       view.bringSubviewToFront(bigButton)  
     }
}

class FirstViewController: UIViewController {

  override func viewDidLoad() {
    super.viewDidLoad()
    (tabBarController as! CustomTabBarController).addCenterButton()
  }

  override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    (tabBarController as! CustomTabBarController).showButton()
  }

  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    let viewController = segue.destinationViewController as! UIViewController

    (tabBarController as! CustomTabBarController).hideButton()
    viewController.hidesBottomBarWhenPushed = true
  }
}

---

我正在处理一个类似的情况，并最终子类化了

UITabBarController

。在子类“

viewdilayoutsubviews

方法中，调用

bringSubviewToFront（view:UIView）

并传入位于选项卡栏后面的视图，解决了这个问题。请确保在

UITabBarController

的视图中调用此方法。

我也有同样的问题。这里有更新吗？