How can I show a popup in a ViewController - ios

Question

I want to show this popup in my view controller and when I push the button go back
This is the part of I want to show the pop up:
#IBAction func entrarAction(_ sender: UIButton) {
sender.isEnabled = false
let l = showLoader()
let user = userTextField.text!
let passwd = passwordTextField.text!
if !validaEntrada(user: user, password: passwd){
// TODO: show errors!
// Show popup here
return
}
let login = VenLogin(usuario: user, contrasenia: passwd)
try! RequestManager.fcReq(url: .login, req: login, res: VenLoginResponse.self) { loginResp, err in
sender.isEnabled = true
l.dismiss(animated: true, completion: {
if let r:VenLoginResponse = loginResp as? VenLoginResponse {
if r.code0 {
let c = self.getAppDelegateContainer()
c.register(from: .loginResponse, value: r)
c.register(from: .tokenJwt, value: r.tokenJwt!)
self.pushServicios()
}
}
})
}
}

Answer 1

Instead of a custom View Controller for your popup you can use an Alert View
#IBAction func entrarAction(_ sender: UIButton) {
sender.isEnabled = false
let l = showLoader()
let user = userTextField.text!
let passwd = passwordTextField.text!
if !validaEntrada(user: user, password: passwd){
// Show popup here
showErrorAlert()
return
// the rest of your code
}
func showErrorAlert() {
let alert = UIAlertController(title: "Usuario o contraseña no válido", message: "", preferredStyle: UIAlertController.Style.alert)
alert.addAction(UIAlertAction(title: "Aceptar", style: UIAlertAction.Style.cancel, handler: nil))
self.present(alert, animated: true, completion: nil)
}
But if you still want to use your custom View Controller use this to show the popup:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let popupErrorLogin = storyboard.instantiateViewController(withIdentifier: "PopupErrorLogin") as! PopupErrorLogin
self.present(popupErrorLogin, animated: true, completion: nil)
And this to close it:
#IBAction func aceptarAction(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
}