Attempt to present ViewController whose view is not in the windows hierarchy

Question

I meet a strange problem: I made 2 view controllers for wich I can switch the view with code:

var currentViewController:UIViewController=UIApplication.shared         


        

Answer 1

Calling function in viewDidAppear helps in my case. Solution for Swift 3:

In your Main Controller:

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    showTutorialModally()
}

func showTutorialModally() {
    let tutorialViewController = TutorialViewController()
    tutorialViewController.modalPresentationStyle = .overCurrentContext
    present(tutorialViewController, animated: true, completion: nil)
}

In your Tutorial Controller:

view.backgroundColor = UIColor.clear
view.isOpaque = false