我正在尝试做一个注册页面,但由于某种原因,当我测试它时,我一直得到同样的错误“致命错误:在解包一个可选值时意外发现nil”行“let username = self.usernameField.text”在模拟器中 . 我知道错误与值为零有关,但无法弄清楚如何解决它请帮助:(
代码=
@IBOutlet weak var emailField: UITextField?
@IBOutlet weak var usernameField: UITextField?
@IBOutlet weak var passwordField: UITextField?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func signUpAction(sender: AnyObject) {
let username = self.usernameField!.text
let password = self.passwordField!.text
let email = self.emailField!.text
let finalEmail = email!.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
// Validate the text fields
if username?.characters.count < 5 {
let alert = UIAlertView(title: "Invalid", message: "Username must be greater than 5 characters", delegate: self, cancelButtonTitle: "OK")
alert.show()
} else if password?.characters.count < 8 {
let alert = UIAlertView(title: "Invalid", message: "Password must be greater than 8 characters", delegate: self, cancelButtonTitle: "OK")
alert.show()
} else if email?.characters.count < 8 {
let alert = UIAlertView(title: "Invalid", message: "Please enter a valid email address", delegate: self, cancelButtonTitle: "OK")
alert.show()
} else {
// Run a spinner to show a task in progress
let spinner: UIActivityIndicatorView = UIActivityIndicatorView(frame: CGRectMake(0, 0, 150, 150)) as UIActivityIndicatorView
spinner.startAnimating()
let newUser = PFUser()
newUser.username = username
newUser.password = password
newUser.email = finalEmail
// Sign up the user asynchronously
newUser.signUpInBackgroundWithBlock({ (succeed, error) -> Void in
// Stop the spinner
spinner.stopAnimating()
if ((error) != nil) {
let alert = UIAlertView(title: "Error", message: "\(error)", delegate: self, cancelButtonTitle: "OK")
alert.show()
} else {
let alert = UIAlertView(title: "Success", message: "Signed Up", delegate: self, cancelButtonTitle: "OK")
alert.show()
dispatch_async(dispatch_get_main_queue(), { () -> Void in
let viewController:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("Home")
self.presentViewController(viewController, animated: true, completion: nil)
})
}
})
1 回答
试试这个...
“AterLoginVC”是您希望在成功登录后实例化的视图控制器的故事板标识符 . 然后,您可以添加if / else语句来评估条件并相应地将错误返回给用户