SampleViewController.swift

final class SampleViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let button = UIButton(type: .System)

        // ...

        button.addTarget(self, action: #selector(SampleViewController.buttonTapped(_:)), forControlEvents: .TouchUpInside)
        view.addSubview(button)
    }

    @objc private func buttonTapped(button: UIButton) {
        print("Selector method called!")
    }
}