Pickerview is showing empty on second click in the textfield, adn when i press Done or Cancel the App crashes

var gender = ["MALE","FEMALE", "Other"]var genderPicker: UIPickerView! = UIPickerView()

// On the first click in the textfield the gender pickerview works fine, but if i press out and then i press again in the gender textfield the picker appears empty.

// And when i press either cancel or Done to dismiss the picker the app crashes with the below error

Unrecognized selector sent to instance” in swift

override func viewDidLoad() {    super.viewDidLoad()    tableViewHeight.constant = screenHeight * 0.7    // Do any additional setup after loading the view.    let toolBar = UIToolbar()    toolBar.barStyle = UIBarStyle.default    toolBar.isTranslucent = true    toolBar.tintColor = UIColor.systemBlue    toolBar.sizeToFit()    let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItem.Style.plain, target: self, action: "donePicker")    let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: nil, action: nil)    let cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItem.Style.plain, target: self, action: "donePicker")    toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)    toolBar.isUserInteractionEnabled = true    genderTxtField.delegate = self    genderPicker!.delegate = self    genderPicker!.dataSource = self    genderTxtField.inputAccessoryView = toolBar    self.genderTxtField.inputView = genderPicker}func donePicker() {    genderTxtField.resignFirstResponder()}

// Delegates Methods

extension InsuranceMethodsSemiViewController: UITextFieldDelegate {    func textFieldShouldBeginEditing(textField: UITextField) -> Bool {        genderPicker.isHidden = false        genderTxtField.inputView = genderPicker;        return false    }    func textFieldDidEndEditing(_ textField: UITextField) {        genderPicker.isHidden = true    }}extension InsuranceMethodsSemiViewController: UIPickerViewDelegate {    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {        return gender[row]    }func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {    genderTxtField.text = gender[row]    self.view.endEditing(true)    pickerView.isHidden = true}}extension InsuranceMethodsSemiViewController: UIPickerViewDataSource {    func numberOfComponents(in pickerView: UIPickerView) -> Int {        return 1    }    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {        return gender.count    }}