I don’t really understand how you can create several VCs programmatically (without using a storyboard) and how you can move between them: transfer data from one VC to another, how you can return to the previous VC, etc. using the button.

Is there any detailed guide or can you briefly explain the main point? On the Internet, there are either answers to specific tasks or only information on how to do this with segway across storyboards, but I did not find detailed full guidance on how to create a VC and what functions are most often used to control VC and transfer data between them .

    1 answer 1

    I will describe everything on an example with two ViewController. Comments in the code give the answer to your questions.

    class ViewController1: UIViewController { override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .white createPresentButton() } //создаем кнопку, с помощью которой будем переходить на новый VC func createPresentButton() { let button = UIButton(type: .system) button.setTitle("Present new VC", for: .normal) button.addTarget(self, action: #selector(presentButtonTapped), for: .touchUpInside) view.addSubview(button) //позиционирование button.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ button.centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: 0), button.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: 0) ]) } @objc func presentButtonTapped() { let vc = ViewController2() //передача данных на новый VC vc.textFromFirstVC = "Test text" //переход на новый VC present(vc, animated: true, completion: nil) } } class ViewController2: UIViewController { //текст с первого VC var textFromFirstVC = "" override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .orange createCloseButton() createTestLabel() } //создаем кнопку, с помощью которой будем закрывать текущий VC func createCloseButton() { let button = UIButton(type: .system) button.setTitle("Close current VC", for: .normal) button.addTarget(self, action: #selector(closeButtonTapped), for: .touchUpInside) view.addSubview(button) //позиционирование button.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ button.centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: 0), button.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: 0) ]) } //label для отоборажения текста с первого VC func createTestLabel() { let label = UILabel(frame: CGRect(x: 0, y: 100, width: 300, height: 100)) label.text = textFromFirstVC view.addSubview(label) label.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ label.centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: 0), label.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: -100) ]) } //действие закрытия текущиего VC @objc func closeButtonTapped() { dismiss(animated: true, completion: nil) } }

    Without a storyboard, we initialize the first ViewController in AppDelegate:

     @UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate { var window: UIWindow? func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { window = UIWindow(frame: UIScreen.main.bounds) window!.makeKeyAndVisible() window!.rootViewController = ViewController1() return true } }

    The result is: ViewController1

    ViewController2

    If you have any questions, ask.