Swift 3：让按钮呈现在ViewController中，怎么办？

Question

I would like my button to reshow the user my on boarding screen since it includes some important instructions to my app. The first time I show my onboarding screen is after the first launch; My current function looks like this:

@IBAction func anleitung(sender: RoundButtons) {

    let appDelegate = AppDelegate()
    appDelegate.window?.rootViewController?.present(OnboardingScreen(), animated: true, completion: nil)

}

This is actually like the 4th way I tried this, but, apparently, none of them worked. Do you know how to do that?

Thanks for having a look! Have a great day!

Answer 1

@IBAction func anleitung(sender: RoundButtons) {
    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    appDelegate.window?.rootViewController?.present(OnboardingScreen(), animated: true, completion: nil)
}