How to get UIWindow value in iOS 14 @main file?

Question

I can able to access didFinishLaunchingWithOptions by below implementation. But, I need UIWindow variable. I don't know how to get it. I'm using Xcode 12 beta. iOS14, SwiftUI lifecycle.


import SwiftUI

@main
struct SSOKit_DemoApp: App {
    
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

class AppDelegate: NSObject, UIApplicationDelegate {
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        
        print("hello world!!!")
        return true
    }
}

I want to integrate a sso sdk. where we need to init the sdk with the UIWindow (root View controller). Previously (swift ui 1.0) I got the UIWindow from SceneDelegate. — Azhagusundaram Tamil, Jun 30 '20 at 08:34

score 21 · Accepted Answer · edited Jun 23 '21 at 02:48

21

From iOS 13 onwards, it's safe to assume that the correct way to obtain a reference to the key window is via UIWindowSceneDelegate.

@main
struct DemoApp: App {
    
    var window: UIWindow? {
        guard let scene = UIApplication.shared.connectedScenes.first,
              let windowSceneDelegate = scene.delegate as? UIWindowSceneDelegate,
              let window = windowSceneDelegate.window else {
            return nil
        }
        return window
    }

    [...]
}

edited Jun 23 '21 at 02:48

aheze

24,434
8
68
125

answered Jun 30 '20 at 11:51

Matteo Pacini

21,796
7
67
74

1

Awesome . Thank you – Azhagusundaram Tamil Jun 30 '20 at 11:57
5

This will probably only work if there is only one window and one scene. That is, it will not work with multitasking on iPad or with macOS. – Nicolai Henriksen Jul 13 '20 at 09:53
Awesome except of course it does not work in App::init – Anton Tropashko Nov 18 '22 at 10:16

score 1 · Answer 2 · answered Jul 21 '21 at 20:23

1

iOS 14.7

@main
struct TestApp: App {

    var window: UIWindow? {
        guard let scene = UIApplication.shared.connectedScenes.first,
              let windowScene = scene as? UIWindowScene else {
            return nil
        }
    
        return .init(windowScene: windowScene)
    }
}

answered Jul 21 '21 at 20:23

Boris

7
2

Please add some explanation. – de. Jul 22 '21 at 22:26

How to get UIWindow value in iOS 14 @main file?

2 Answers2

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