UIWindow overlay not visible

Question

Tring to add an overlay window to the key UIWindow in the IOS app. However, it seems that the new overlay UIWindow is not anywhere visible.

It seems that it is being added successfully though, based on lldb:

(lldb) po UIApplication.shared.windows
▿ 2 elements
  - 0 : <UIWindow: 0x7fdfd3d0aec0; frame = (0 0; 375 667); gestureRecognizers = <NSArray: 0x60800004d680>; layer = <UIWindowLayer: 0x608000220980>>
  - 1 : <UIWindow: 0x7fdfd3c0d010; frame = (0 0; 375 667); gestureRecognizers = <NSArray: 0x60000004c9c0>; layer = <UIWindowLayer: 0x6000002216e0>>

In the debug,

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let vc = UIViewController()
    vc.view.backgroundColor = UIColor.blue

    let window = UIWindow()
    window.frame = self.view.bounds
    window.backgroundColor = UIColor.blue
    window.windowLevel = UIWindowLevelStatusBar
    window.rootViewController = vc
    window.isHidden = false
}

Would appreciate any sort of hint/help thanks

Answer 1

Your window is being deallocated after your viewDidLoad() method exits. You need to strongly retain your second window.