В Быстрых 4 или 5 можно использовать как..

class ViewController: UIViewController {

  override func viewDidLoad() {
    super.viewDidLoad()

    //Key borad dismiss
    let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "dismissKeyboard")
    tap.cancelsTouchesInView = false
    view.addGestureRecognizer(tap)
  }

 //Key board hide on outside the textfield
 @objc func dismissKeyboard() {
    //Causes the view (or one of its embedded text fields) to resign the first responder status.
    view.endEditing(true)
  }
}