Xcode9学习笔记17 - 导航视图控制器UINavigationController

override func viewDidLoad() {
super.viewDidLoad()

// Do any additional setup after loading the view.

self.title = "First Page"
self.view.backgroundColor = UIColor.brown

//设置右上角导航按钮的样式和功能，点击时，页面跳转到第二个视图控制器
self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Next", style: UIBarButtonItemStyle.plain, target: self, action: #selector(FirstSubViewController.nextPage))
}

@objc func nextPage() {
let viewController = SecondSubViewController()//初始化第二个视图控制器对象

//将第二个视图控制器，压入导航视图控制器中，实现页面的跳转
self.navigationController?.pushViewController(viewController, animated: true)
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}

override func viewDidLoad() {
super.viewDidLoad()

// Do any additional setup after loading the view.

self.title = "Second Page"
self.view.backgroundColor = UIColor.purple
}

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.

let viewController = FirstSubViewController()//实例化第一个视图控制器对象

//接着初始化导航视图控制器对象，并将第一个视图控制器对象，作为导航根视图控制器
let navigationController = UINavigationController(rootViewController: viewController)
self.window?.rootViewController = navigationController//将导航视图控制器对象，作为当前窗口的根视图控制器

return true
}