Ios/swift/ナビゲーションバー

• AppDelegate.swift

class AppDelegate: UIResponder, UIApplicationDelegate {
   var window: UIWindow?
   var myNavigationController: UINavigationController?
   func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
       let first: ViewController = ViewController()
       myNavigationController = UINavigationController(rootViewController: first)
       self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
       self.window?.rootViewController = myNavigationController
       self.window?.makeKeyAndVisible()
       return true
   }

• ViewController.swift

class ViewController: UIViewController {
   var addBtn: UIBarButtonItem!
   override func viewDidLoad() {
       super.viewDidLoad()
       self.title = "Home"
       addBtn = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: #selector(ViewController.onClickNavButton))
       self.navigationItem.rightBarButtonItem = addBtn
   }
   func onClickNavButton() {
       let second = SecondViewController()
       self.navigationController?.pushViewController(second, animated: true)
   }

• SecondViewController.swift

import UIKit
class SecondViewController: UIViewController {
   override func viewDidLoad() {
       super.viewDidLoad()
       self.view.backgroundColor = .redColor()
       self.title = "Second"
   }
   override func didReceiveMemoryWarning() {
       super.didReceiveMemoryWarning()
   }
}