尝试呈现AlertController时的窗口层次结构消息

Question

我有一个用于管理与Firebase（注册，登录，保存数据）连接的swift文件。在此文件中，使用一些AlertController通知用户取决于来自Firebase的邮件（错误的电子邮件格式，已使用的电子邮件）。问题是，当一些alerController有露面，他们收到此消息：

Warning: Attempt to present *** on *** whose view is not in the window hierarchy! 

一个注册的ViewController是当前视图，该视图链接到另一个特定的文件。我已经在Stackoverflow和Google上的“windows层次结构”中读了很多，并尝试了不同的东西。

我和用于注册的类似代码有相同的问题。我从这种方式去呈现alertController：

present(alerInvalidEmail, animated: true, completion: nil) 

到一个：

UIApplication.shared.keyWindow?.rootViewController?.present(alertInvalidEmail, animated: true, completion: nil)

，现在它工作正常，但它不符合我的注册工作的部分。 我想它与当前的ViewController有关，但找不到我的方式。

这里我的代码从网络文件：

struct NetworkingService { 

var databaseRef: FIRDatabaseReference! { 
    return FIRDatabase.database().reference() 
} 
var storageRef: FIRStorageReference! { 
    return FIRStorage.storage().reference() 
} 


func signUp(email: String, pseudo:String, password: String, data: NSData!){ 

    FIRAuth.auth()?.createUser(withEmail: email, password: password, completion: { (user, error) in 

     if error != nil { 
      print(error!.localizedDescription) 


     if let SignUperrCode = FIRAuthErrorCode(rawValue: error!._code) { 
      switch SignUperrCode { 

      case .errorCodeInvalidEmail: 
       let alertInvalidEmail = UIAlertController(title: "Email validation", message: "You have entered an malformed adress", preferredStyle: .alert) 
       alertInvalidEmail.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action:UIAlertAction) in 
        print("Invalid email") 
       })) 

       UIApplication.shared.keyWindow?.rootViewController?.present(alertInvalidEmail, animated: true, completion: nil) 


      case .errorCodeEmailAlreadyInUse: 
       let alertUsedEmail = UIAlertController(title: "Email validation", message: "This email is already used", preferredStyle: .alert) 
       alertUsedEmail.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action:UIAlertAction) in 
        print("In use") 
       })) 
        UIApplication.shared.keyWindow?.rootViewController?.present(alertUsedEmail, animated: true, completion: nil) 


      default: 
       print("Create User Error: \(error!)") 
      }} 

     } else { 
      self.setUserInfo(user: user, pseudo : pseudo, password: password, data: data) 


      let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "nextView") 

      (UIApplication.shared.keyWindow?.rootViewController?.present(vc, animated: true, completion: nil))! 
      print("user signed up successfully") 

     } 
    }) 
} 

这里是代码使用调用从视图控制器文件中的注册功能。

@IBAction func signUpAction(_ sender: Any) { 

    let data = UIImageJPEGRepresentation(self.UserImageView.image!, 0.8) 

    networkingService.signUp(email: emailTextField.text!, pseudo: pseudoTextField.text!, password: passwordTextField.text!, data: data! as NSData) 

也许我不是在右边的窗口，但相同的代码工作正常的注册部分。

在此先感谢您的帮助。

Answer 1

添加一个新的参数类型的UIViewController

func signUp(email: String, pseudo:String, password: String, data: NSData!,viewController: UIViewController){ 

     FIRAuth.auth()?.createUser(withEmail: email, password: password, completion: { (user, error) in 

      if error != nil { 
       print(error!.localizedDescription) 


      if let SignUperrCode = FIRAuthErrorCode(rawValue: error!._code) { 
       switch SignUperrCode { 

       case .errorCodeInvalidEmail: 
        let alertInvalidEmail = UIAlertController(title: "Email validation", message: "You have entered an malformed adress", preferredStyle: .alert) 
        alertInvalidEmail.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action:UIAlertAction) in 
         print("Invalid email") 
        })) 

        viewController.present(alertInvalidEmail, animated: true, completion: nil) 


       case .errorCodeEmailAlreadyInUse: 
        let alertUsedEmail = UIAlertController(title: "Email validation", message: "This email is already used", preferredStyle: .alert) 
        alertUsedEmail.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action:UIAlertAction) in 
         print("In use") 
        })) 
         viewController.present(alertUsedEmail, animated: true, completion: nil) 


       default: 
        print("Create User Error: \(error!)") 
       }} 

      } else { 
       self.setUserInfo(user: user, pseudo : pseudo, password: password, data: data) 


       let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "nextView") 

       (UIApplication.shared.keyWindow?.rootViewController?.present(vc, animated: true, completion: nil))! 
       print("user signed up successfully") 

      } 
     }) 
    } 

您的viewController功能并把它作为

networkingService.signUp(email: emailTextField.text!, pseudo: pseudoTextField.text!, password: passwordTextField.text!, data: data! as NSData, viewController: self)