ios - setNavigationBarHidden animation not working as expected on iPhone X

Question

I have code that enters full screen mode by hiding the UINavigationController's navigation bar. I want a smooth animated zooming effect when entering full screen. I use setNavigationBarHidden(_:animated:). This has all worked fine up to now, even on iOS 11, but on iPhone X the animation is not working well. On hiding, there is no animation and the nav bar just disappears. On unhiding, it does animate but the nav bar appears at a slower rate than the navigation controller's content area reduces, so an ugly black background shows through the navigation bar area during the animation.

I can recreate this in a simple test app. I have a UIViewController embedded in a UINavigationController.

Storyboard

• UINavigationController Navigation Bar: Style == Black; Translucent OFF
• UIViewController: Extend Edges: all options OFF.

I have tried all the combinations of Adjust Scroll View Insets and Extend Edges that I can think of but they made no difference.

Code

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    setFullScreen(on: fullScreen, animated: animated)
}

override var prefersStatusBarHidden: Bool
{
    return fullScreen
}

override var preferredStatusBarStyle: UIStatusBarStyle
{
    return .lightContent
}

@IBAction func onToggleNavBarVisibility(_ sender: Any) {

    if let navBarHidden = self.navigationController?.isNavigationBarHidden {
        // Toggle the state
        fullScreen = !navBarHidden

        setFullScreen(on: fullScreen, animated: true)
    }
}

private func setFullScreen(on : Bool, animated : Bool) {

    self.navigationController?.setNavigationBarHidden(on, animated: animated)
    self.setNeedsStatusBarAppearanceUpdate()
}

Answer 1

In your case you are using both barTintColor & navigationBarStyle with Show Hide animation. barTintColor overrides the value implied by the Style attribute You should select either barTintColor or navigationBarStyle In below code i have just used barTintColor & navigationBarStyle is default with Transulent.

    var fullScreen = false{
      didSet{
        self.setNeedsStatusBarAppearanceUpdate()
     }
   }
    override func viewDidLoad() {
        super.viewDidLoad()
        title = "Navigation Bar"
        navigationController?.navigationBar.barTintColor = .red
    }
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(true)
        setFullScreen(on: fullScreen, animated: animated)
    }
    @IBAction func onToggleNavBarVisibility(_ sender: Any) {
        if let navBarHidden = 
          self.navigationController?.isNavigationBarHidden {
            // Toggle the state
            fullScreen = !navBarHidden
            setFullScreen(on: fullScreen, animated: true)
        }
    }
    private func setFullScreen(on : Bool, animated : Bool) {
        self.navigationController?.setNavigationBarHidden(on, animated: animated)
        self.setNeedsStatusBarAppearanceUpdate()
    }

EDIT: If you want to hide status bar- use prefersStatusBarHidden with the bool value. & use setNeedsStatusBarAppearanceUpdate

   override var prefersStatusBarHidden: Bool {
        return fullScreen
    }

https://developer.apple.com/documentation/uikit/uinavigationbar