Я пытаюсь создать приложение с помощью Swift и Parse. Я использую Xcode 7 и Swift 2. Я хочу показать предупреждающее сообщение, когда пользователю не удалось войти в систему, вот моя функция:
func logInViewController(logInController: PFLogInViewController, didFailToLogInWithError error: NSError?){
let alertLoginFailed = UIAlertController(title: "Login Failed", message: "Your username or password is invalid!", preferredStyle: UIAlertControllerStyle.Alert)
alertLoginFailed.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alertLoginFailed, animated: true, completion: nil)
print("Login failed.........!")
}
Но у меня есть эта ошибка при запуске в эмуляторе:
2015-10-02 11:32:39.988 RedString[2089:886501] Warning: Attempt to present <UIAlertController: 0x7a934400> on <MyProject.ViewController: 0x7b985150> whose view is not in the window hierarchy!
Login failed.........!
Я гуглил об этом, но не нашел четкого решения.
Вот весь мой класс:
import UIKit
import Parse
import ParseUI
class ViewController: UIViewController, PFLogInViewControllerDelegate, PFSignUpViewControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(animated: Bool) {
self.setupLoginView()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func logInViewController(logInController: PFLogInViewController, didLogInUser user: PFUser){
self.dismissViewControllerAnimated(true, completion: nil)
}
func logInViewController(logInController: PFLogInViewController, didFailToLogInWithError error: NSError?){
let alertLoginFailed = UIAlertController(title: "Login Failed", message: "Your username or password is invalid!", preferredStyle: UIAlertControllerStyle.Alert)
alertLoginFailed.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alertLoginFailed, animated: true, completion: nil)
print("Login failed.........!")
}
func signUpViewController(signUpController: PFSignUpViewController, didSignUpUser user: PFUser){
self.dismissViewControllerAnimated(true, completion: nil)
}
func signUpViewController(signUpController: PFSignUpViewController, didFailToSignUpWithError error: NSError?){
print("Sign up failed.........!")
}
func setupLoginView(){
if(PFUser.currentUser() == nil){
let loginViewController = PFLogInViewController()
loginViewController.delegate = self
let signUpViewController = PFSignUpViewController()
signUpViewController.delegate = self
loginViewController.logInView!.logo = UIImageView(image: UIImage(named:"logo.png"))
loginViewController.signUpController = signUpViewController
self.presentViewController(loginViewController, animated: true, completion: nil)
}else{
print("login as: " + PFUser.currentUser()!.username!)
//prepare new view here
}
}
}