Duo Duo - 1 year ago 40
iOS Question

UILongPressGestureRecognizer pass argument with selector

I currently have an action sheet made using SimpleAlert that generates a list of buttons. The buttons recognize taps and long presses. On the long press I am trying to pass the button as a sender through a selector in order to access the button tag in another function, however it keeps giving me this error:


2017-07-26 11:27:15.173 hitBit[8614:134456] *** Terminating app due to
uncaught exception 'NSInvalidArgumentException', reason:
'-[LongTap(sender: button]: unrecognized selector sent to instance
0x7f9c458ccc00'


How can I pass objects such as buttons through the selector? If there is a solution that allows me to just pass through an integer, that would work fine as well.

@IBAction func tapMGName(_ sender: Any) {
let mgController = MouthguardSelectionController(title: "Go to:", message: nil, style: .actionSheet)

//For every MG, make an action that will navigate you to the mouthguard selected
for i in 0...self.getNumberDevices() - 1 {
mgController.addAction(index: i, (AlertAction(title: mg_Name[i], style: .ok) { action -> Void in
self.changeMouthguard(index: i)
self.dismiss(animated: true, completion: nil)
}))
}


Code that creates the custom action sheet and generates actions for the list

override func configureButton(_ style :AlertAction.Style, forButton button: UIButton, index: Int) {
super.configureButton(style, forButton: button)
cur_mg_ID_index = index
let longGesture = UILongPressGestureRecognizer(target: self, action: "LongTap(sender: button") //Long function will call when user long press on button.

if (button.titleLabel?.font) != nil {
switch style {
case .ok:
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 20)
button.tag = index
button.addGestureRecognizer(longGesture)
case .cancel:
button.backgroundColor = UIColor.darkGray
button.setTitleColor(UIColor.white, for: .normal)
case .default:
button.setTitleColor(UIColor.lightGray, for: .normal)
default:
break
}
}
}

func LongTap(sender: UIButton) {
print(sender.tag)
let nameChanger = AlertController(title: "Change name of ya boy", message: nil, style: .alert)
nameChanger.addTextFieldWithConfigurationHandler() { textField in
textField?.frame.size.height = 33
textField?.backgroundColor = nil
textField?.layer.borderColor = nil
textField?.layer.borderWidth = 0
}

nameChanger.addAction(.init(title: "Cancel", style: .cancel))
nameChanger.addAction(.init(title: "OK", style: .ok))

present(nameChanger, animated: true, completion: nil)
}


Code within the custom SimpleAlert action sheet

Answer Source

Try this and see,

override func configureButton(_ style :AlertAction.Style, forButton button: UIButton, index: Int) {
    super.configureButton(style, forButton: button)
    cur_mg_ID_index = index

    // Edited line....
    let longGesture = UILongPressGestureRecognizer(target: self, action: #selector(self.longTap(_:))) //Long function will call when user long press on button.
    if (button.titleLabel?.font) != nil {
        switch style {
        case .ok:
            button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 20)
            button.tag = index
            button.addGestureRecognizer(longGesture)
        case .cancel:
            button.backgroundColor = UIColor.darkGray
            button.setTitleColor(UIColor.white, for: .normal)
        case .default:
            button.setTitleColor(UIColor.lightGray, for: .normal)
        default:
            break
        }
    }
}

 // Edited line....
func longTap(_ gesture: UILongPressGestureRecognizer) {

     // Edited line....
    guard let sender = gesture.view as? UIButton else {
            print("Sender is not a button")
            return
    }

    print(sender.tag)


    let nameChanger = AlertController(title: "Change name of ya boy", message: nil, style: .alert)
    nameChanger.addTextFieldWithConfigurationHandler(){textField in
        textField?.frame.size.height = 33
        textField?.backgroundColor = nil
        textField?.layer.borderColor = nil
        textField?.layer.borderWidth = 0
    }
    nameChanger.addAction(.init(title: "Cancel", style: .cancel))
    nameChanger.addAction(.init(title: "OK", style: .ok))
    present(nameChanger, animated: true, completion: nil)
}
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