How to change font and its size of a label on Navigation Bar - ios8 #swift

Question

Cannot find how to change font or its size of a Navigation Bar, And also there's no option in Attributes Inspector.

I am using OSX Yosemite Xcode and Programming language is Swift

Answer 1

class TestViewController: UIViewController {
    //
    @IBOutlet weak var myNavigationBar: UINavigationBar! // created with a ctrl+drag

    override func viewDidLoad() {
        super.viewDidLoad()
        //
        self.myNavigationBar.titleTextAttributes = [ NSFontAttributeName: UIFont(name: "Helvetica Neue", size: 24)!]    
}