App crashes after push notification is tapped when app is killed

Question

I am attempting to launch a specific viewController in my CustomTabBarController after receiving remote notifications. But somehow, the app always crashes when the app is killed.

Meaning to say, kill the app -> received push notifications -> tap the notifications -> app launches and crashed. This also happens when I tap the notification from the lockscreen.

I am able to execute when the app is in the background, but not when the app is killed. My code so far:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

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

    ...

    if let remoteNotification = launchOptions?[UIApplicationLaunchOptionsKey.remoteNotification] as? NSDictionary {
        guard let rootViewController = self.window?.rootViewController as? CustomTabBarController else {
            return true
        }
        rootViewController.selectedIndex = 1

    }

    return true
}

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

    if application.applicationState == .background || application.applicationState == .inactive {

        guard let rootViewController = self.window?.rootViewController as? CustomTabBarController else {
            return
        }
        rootViewController.selectedIndex = 1
    }        
}

I've followed this post to check the launchOptions, but it still crash. Can anyone advice pls?

Answer 1

Comment these 2 lines

// window = UIWindow(frame: UIScreen.main.bounds)
// window?.makeKeyAndVisible()

as overriding the window property destroys the initialization from storyboard (makes rootVC nil) and before return true window must have one