How to show a ViewController in Swift only ones after downloading?

Question

I am creating an App which features an Onboarding. This Onboarding takes place on a ViewController with only this specific purpose, that's why I only want the ViewController to show up ones after downloading the app.(the main app consists out of only one ViewController)

Here is what I've done so far:

1) I delete the storyboard entry point in the storyboard file

2) entered the Storyboard ID for each of the two ViewController

3) coded in the AppDelegate file that the onboarding ViewContoller only should show up the first time after the download

My problem: When running the app on the simulator it only shows a black screen

I already made sure that the Indentifiers and the name of the storyboard are correct.

(below my AppDelegate.swift file)

import UIKit
import Firebase
import FirebaseDatabase
import paper_onboarding


@UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate {


    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.


        FirebaseApp.configure()


        window = UIWindow(frame: UIScreen.main.bounds)

        let sb = UIStoryboard(name: "Main", bundle: nil)
        var initialViewController = sb.instantiateViewController(withIdentifier: "Onboarding")



        let userDefaults = UserDefaults.standard

         if userDefaults.bool(forKey: "onboardingComplete") {
           initialViewController = sb.instantiateViewController(withIdentifier: "MainApp")
          }


        window?.rootViewController = initialViewController
        window?.makeKeyAndVisible()




        return true

    }

    // MARK: UISceneSession Lifecycle

    func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
        // Called when a new scene session is being created.
        // Use this method to select a configuration to create the new scene with.
        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    }

    func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {
        // Called when the user discards a scene session.
        // If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
        // Use this method to release any resources that were specific to the discarded scenes, as they will not return.
    }


}
``

Answer 1

The solution for this problem is not to use the AppDelegate.swift file but the SceneDelegate.swift file.

below my SceneDelegate.swift file

import UIKit

class SceneDelegate: UIResponder, UIWindowSceneDelegate {

    var window: UIWindow?


    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
        // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
        // This delegate does not imply the connecting scene or session are new (see`application:configurationForConnectingSceneSession` instead).

        let sb = UIStoryboard(name: "Main", bundle: nil)
        var initialViewController = sb.instantiateViewController(withIdentifier: "Onboarding")


        let userDefaults = UserDefaults.standard

                if userDefaults.bool(forKey: "onboardingComplete") {
                   initialViewController = sb.instantiateViewController(withIdentifier: "MainApp")
                 }




        if let windowScene = scene as? UIWindowScene {

            let window = UIWindow(windowScene: windowScene)
             window.rootViewController = initialViewController
             self.window = window
            window.makeKeyAndVisible()
         }




        guard let _ = (scene as? UIWindowScene) else { return }
    }

    func sceneDidDisconnect(_ scene: UIScene) {
        // Called as the scene is being released by the system.
        // This occurs shortly after the scene enters the background, or when its session is discarded.
        // Release any resources associated with this scene that can be re-created the next time the scene connects.
        // The scene may re-connect later, as its session was not neccessarily discarded (see `application:didDiscardSceneSessions` instead).
    }

    func sceneDidBecomeActive(_ scene: UIScene) {
        // Called when the scene has moved from an inactive state to an active state.
        // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
    }

    func sceneWillResignActive(_ scene: UIScene) {
        // Called when the scene will move from an active state to an inactive state.
        // This may occur due to temporary interruptions (ex. an incoming phone call).
    }

    func sceneWillEnterForeground(_ scene: UIScene) {
        // Called as the scene transitions from the background to the foreground.
        // Use this method to undo the changes made on entering the background.
    }

    func sceneDidEnterBackground(_ scene: UIScene) {
        // Called as the scene transitions from the foreground to the background.
        // Use this method to save data, release shared resources, and store enough scene-specific state information
        // to restore the scene back to its current state.
    }


}