Presenting a specific view controller from AppDelegate

Question

I am trying to present a view controller (a passcode request type view) every time my app becomes active. Once the correct passcode is entered, it should pop off the stack.

Answer 1

Swift version of Quick and generalised way:

getRootViewController().presentViewController(messageVC, animated: true, completion: nil)

func getRootViewController() -> UIViewController
{
    return (UIApplication.sharedApplication().delegate?.window??.rootViewController)!
}