If we want to disable all the actions like Copy, Paste, Replace, Select, etc from UITextField then we can use following custom text field:

class CustomTextField: UITextField {

var enableLongPressActions = false

required init(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)!
}

override init(frame: CGRect) {
    super.init(frame: frame)
}

override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
    return enableLongPressActions
}
}

Using enableLongPressActions property, we can enable all actions any time later, if needed.