Prevent screen capture in an iOS app

I’ve just wrote simple extension of UIView that allows to hide it from screen-capturing, Airplay mirroring and so on. The solution uses ability of UITextField to hide a password from capturing.

extension UIView {
    func makeSecure() {
        DispatchQueue.main.async {
            let field = UITextField()
            field.isSecureTextEntry = true
            self.addSubview(field)
            field.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
            field.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
            self.layer.superlayer?.addSublayer(field.layer)
            field.layer.sublayers?.first?.addSublayer(self.layer)
        }
    }
}

using:

class ViewController: UIViewController {

   var secureView: UIView!

   override func viewDidLoad() {
      super.viewDidLoad()

      secureView.makeSecure()
   }
}

I’ll be grateful if someone explains how Apple does this magic inside.