presentViewController has no navigationController swift

Question

My transition to the next view is like this:

if let navigationController = navigationController {
        if let storyboard:UIStoryboard = UIStoryboard(name: "myStoryboard", bundle: nil) {

            if let vc = storyboard.instantiateViewControllerWithIdentifier("myViewController") as? MyViewController {
                dispatch_async(dispatch_get_main_queue()) {
                    navigationController.presentViewController(vc, animated: true, completion: nil)
                }
            }
        }
    }

This works fine. I want this kind of transition. But when I call following code in MyViewController, the NavigationController is nil:

if let navigationController = navigationController {
       print("yeah i have a nc")
    } else {
         print("its nil") //this will call
    }

When I use navigationController.pushViewController(vc, animated: true) everything works fine. But I really want the transition. Is this a wrong implementation on my side or is presentViewController always without a navigationController? If yes, what can I do?

My Controller A is already embedded in a navigationController. I use navigationController.presentViewController to go to MyViewController. And from MyViewController I want to push to a next ViewController C.

Answer 1

SOLUTION THAT WORKED FOR ME

I don't know why, but when you use the presentViewController you have to define a new(?) root for your navigationController.

In this context I understood Ahmad Fs answer.

if let storyboard:UIStoryboard = UIStoryboard(name: "myStoryboard", bundle: nil) {
        if let vc = storyboard.instantiateViewControllerWithIdentifier("MyViewController") as? MyViewController {
            if let navController:UINavigationController = UINavigationController(rootViewController: vc) {
                dispatch_async(dispatch_get_main_queue()) {
                    self.presentViewController(navController, animated:true, completion: nil)
                }
            }
        }
    }

SWIFT 3

    let storyboard = UIStoryboard(name: UIConstants.Storyboards.registration, bundle: nil)
    if let vc = storyboard.instantiateViewController(withIdentifier: "YourViewControllerIdentifier") as? YourViewController {

        let navigationController = UINavigationController(rootViewController: vc)
        DispatchQueue.main.async {
            navigationController.present(vc, animated: true)
        }
    }

I found "my" solution here