Stack在这个问题上有很多问题,但他们都没有解决我遇到的问题。iOS 8 Swift 1.2 and Parse - 尝试在ViewController上呈现UIAlertController,它的视图不在窗口层次结构中
我使用ParseUI作为我的应用程序的登录和注册部分。我想像发生的是UIAlertController
当用户(例如)没有在用户名和密码字段中输入任何文本时显示。
这里是我的MasterViewController
代码:
class MasterViewController: UIViewController, PFLogInViewControllerDelegate,
PFSignUpViewControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
if (PFUser.currentUser() == nil) {
var logInViewController = LoginViewController()
logInViewController.delegate = self
var signUpViewController = SignUpViewController()
signUpViewController.delegate = self
logInViewController.signUpController = signUpViewController
self.presentViewController(logInViewController, animated: true, completion: nil)
}
}
func logInViewController(logInController: PFLogInViewController,
shouldBeginLogInWithUsername username: String, password: String) -> Bool {
if (!username.isEmpty || !password.isEmpty) {
return true
} else {
let alertController = UIAlertController(title: "Failed to login.",
message: "Login Failure. Please try again.", preferredStyle: .Alert)
let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)
alertController.addAction(defaultAction)
self.presentViewController(alertController, animated: true, completion: nil)
return false
}
}
func logInViewController(logInController: PFLogInViewController,
didFailToLogInWithError error: NSError?) {
println("Failed to log in.")
}
func signUpViewController(signUpController: PFSignUpViewController,
shouldBeginSignUp info: [NSObject : AnyObject]) -> Bool {
if let password = info["password"] as? String {
return count(password.utf16) >= 8
} else {
return false
}
}
func signUpViewController(signUpController: PFSignUpViewController,
didFailToSignUpWithError error: NSError?) {
println("Failed to sign up.")
}
func logInViewController(logInController: PFLogInViewController,
didLogInUser user: PFUser) {
let installation = PFInstallation.currentInstallation()
installation["user"] = PFUser.currentUser()
installation.saveInBackground()
self.dismissViewControllerAnimated(true, completion: nil)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func signUpViewControllerDidCancelSignUp(signUpController:
PFSignUpViewController) {
println("User dismissed signup.")
}
}
阅读这似乎像它会是回答其他用户的回答后,我添加了下面的类,以我的工作区:
import Foundation
class AlertHelper: NSObject {
func showAlert(fromController controller: MasterViewController) {
var alert = UIAlertController(title: "abc", message: "def", preferredStyle: .Alert)
controller.presentViewController(alert, animated: true, completion: nil)
}
}
而且然后相应地修改我的方法:
func logInViewController(logInController:PFLogInViewController, shouldBegin LogInWithUsername用户名:字符串,密码:字符串) - >布尔{
if (!username.isEmpty || !password.isEmpty) {
return true
} else {
let alertController = UIAlertController(title: "Failed to login.",
message: "Login Failure. Please try again.", preferredStyle: .Alert)
let defaultAction = UIAlertAction(title: "OK", style: .Default, handler: nil)
alertController.addAction(defaultAction)
var alert = AlertHelper()
alert.showAlert(fromController: self)
return false
}
}
在这一点上,我不太清楚自己能做什么。有一个想法是以编程方式将UILabel
添加到我的LoginViewController
和SignUpViewController
,并根据用户登录和注册的错误(或缺少)更改内容,但我希望发出警报。
编辑:这是我的LoginViewController
中的代码。它被分类为了定制外观。我的SignUpViewController
的代码几乎完全相同。
进口的UIKit 进口解析 进口ParseUI
class LoginViewController: PFLogInViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = ckPurple
let label = UILabel()
label.textColor = UIColor.whiteColor()
label.text = "Welcome."
label.sizeToFit()
logInView?.logo = label
// Do any additional setup after loading the view.
}
您的回答非常接近。相反,它是'loginController.presentViewController(alertController,animated:true,completion:nil)'(在注册的情况下,它是'signUpController',因为我必须在委托方法中引用'PFLoginViewController'和PFSignupViewController'。 – damianesteban
好的,我把'loginViewController'改为'loginController'。很高兴我的回答对你有帮助,请考虑标记为正确。 – johnpatrickmorgan