Set rootViewController of UINavigationController by method other than initWithRootViewController

Question

How Do I set the rootViewController of UINavigationController by a method other than initWithRootViewController?

I want use

Answer 1

In swift 3.0 xcode8.1

in general settings delete in Main Interface: Main <-this after Main Interface:

class AppDelegate...

 var window: UIWindow?

    fun application...

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