Correct way to get the screen size on iOS, after UIScreen.main deprecation

Question

I always used UIScreen.main.bounds.size to get the screen size on iOS and worked fine.

Now (in iOS 16, I believe) when I try to access the screen size with the "main" instance of UIScreen a warning is displayed:

"main' will be deprecated in a future version of iOS: Use a UIScreen instance found through context instead: i.e, view.window.windowScene.screen

So my question is: What is the correct way to get the screen size? for simplicity let's imagine we are on the iPhone with, consequently, only one screen available. Thank you

This article might be helpful: https://designcode.io/swiftui-handbook-detect-screen-size — wzso, Jul 20 '23 at 23:23

score 2 · Accepted Answer · answered Jan 07 '23 at 03:25

Per Apple discussion on UIScreen.main deprecation:

Apple discourages the use of this symbol. Use a UIScreen instance found through context instead. For example, reference the screen that displays a view through the screen property on the window scene managing the window containing the view.

Here is an extension to find the UIScreen instance through context:

extension UIViewController {
  func screen() -> UIScreen? {
    var parent = self.parent
    var lastParent = parent
    
    while parent != nil {
      lastParent = parent
      parent = parent!.parent
    }
    
    return lastParent?.view.window?.windowScene?.screen
  }
}

For reference, this is the same UIScreen instance associated with the windowScene in the SceneDelegate:

  func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {

    guard let windowScene = (scene as? UIWindowScene) else { return }
    
    window = UIWindow(frame: windowScene.coordinateSpace.bounds)
    window?.windowScene = windowScene
    window?.rootViewController = ViewController()
    window?.makeKeyAndVisible()
    
    let screen = windowScene.screen
    
    configureNavigationBar()
  }

score 1 · Answer 2 · edited Nov 21 '22 at 15:27

1

From a ViewController:

let screenSize = self.view.window?.windowScene?.screen.bounds.size

edited Nov 21 '22 at 15:27

ZGski

2,398
1
21
34

answered Nov 17 '22 at 06:37

J. Coder

31
6

1

So this is a solution only if you still use the old ViewController lifecycle? Thanks! – Luca Nov 17 '22 at 07:52

score 1 · Answer 3 · answered Jul 20 '23 at 08:39

extension UIWindow {
    static var current: UIWindow? {
        for scene in UIApplication.shared.connectedScenes {
            guard let windowScene = scene as? UIWindowScene else { continue }
            for window in windowScene.windows {
                if window.isKeyWindow { return window }
            }
        }
        return nil
    }
}


extension UIScreen {
    static var current: UIScreen? {
        UIWindow.current?.screen
    }
}

This way, you can use this anywhere, just like you could with the UIScreen.main.

usage

UIScreen.current?.bounds.size

Correct way to get the screen size on iOS, after UIScreen.main deprecation

3 Answers3

usage

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