ios - displaying a uiviewcontroller embeded in a navigation controller with button tapped

Question

I am trying to present a viewcontroller embedded in a navigation caontroller by tapping a button. Everytime I tap the button the app crashes saying Could not cast value of type 'UINavigationController' (0x11320f420) to

my code to display the Viewcontroller

@IBAction func skipButtonTapped(_ : UIButton) {
    let viewController: CategoryVC = UIStoryboard(name: "CategorySB", bundle: nil).instantiateViewController(withIdentifier: Constants.CATEGORY_VC) as! CategoryVC
    self.present(viewController, animated: true, completion: nil)
}

any help thanks

Answer 1

You can try

let nav = UIStoryboard(name: "CategorySB", bundle: nil).instantiateViewController(withIdentifier: Constants.CATEGORY_VC) as! UINavigationController 
self.present(nav, animated: true, completion: nil)

//

if you wan to access root

if let cat = nav.topViewController as? CategoryVC {

}