Como adicionar TextField a UIAlertController em Swift

Estou tentando mostrar um UIAlertControllercom um UITextView. Quando eu adiciono a linha:

    //Add text field
    alertController.addTextFieldWithConfigurationHandler { (textField) -> Void in
    }        

Recebo um Runtimeerro:

erro fatal: inesperadamente encontrado nulo ao desempacotar um valor opcional

    let alertController: UIAlertController = UIAlertController(title: "Find image", message: "Search for image", preferredStyle: .Alert)

    //cancel button
    let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .Cancel) { action -> Void in
        //cancel code
    }
    alertController.addAction(cancelAction)

    //Create an optional action
    let nextAction: UIAlertAction = UIAlertAction(title: "Search", style: .Default) { action -> Void in
        let text = (alertController.textFields?.first as! UITextField).text
        println("You entered \(text)")
    }
    alertController.addAction(nextAction)

    //Add text field
    alertController.addTextFieldWithConfigurationHandler { (textField) -> Void in
        textField.textColor = UIColor.greenColor()
    }
    //Present the AlertController
    presentViewController(alertController, animated: true, completion: nil)

Isso é apresentado dentro do meu ViewControlleratravés de um IBAction.

Eu baixei o código daqui e funciona bem. Copiei e colei esse método em meu código e ele falha. A presença de si mesmo na última linha não tem impacto.

Swift 5.1

alert.addTextField { (textField) in
    textField.placeholder = "Enter First Name"
}

Use este código, estou executando este código em meu aplicativo com sucesso.

@IBAction func addButtonClicked(sender : AnyObject){
    let alertController = UIAlertController(title: "Add New Name", message: "", preferredStyle: UIAlertControllerStyle.Alert)
    alertController.addTextFieldWithConfigurationHandler { (textField : UITextField!) -> Void in
        textField.placeholder = "Enter Second Name"
    }
    let saveAction = UIAlertAction(title: "Save", style: UIAlertActionStyle.Default, handler: { alert -> Void in
        let firstTextField = alertController.textFields![0] as UITextField
        let secondTextField = alertController.textFields![1] as UITextField
    })
    let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Default, handler: {
        (action : UIAlertAction!) -> Void in })
    alertController.addTextFieldWithConfigurationHandler { (textField : UITextField!) -> Void in
        textField.placeholder = "Enter First Name"
    }
    
    alertController.addAction(saveAction)
    alertController.addAction(cancelAction)
    
    self.presentViewController(alertController, animated: true, completion: nil)
}

Editado: versão Swift 3.0

@IBAction func addButtonClicked(_ sender: UIButton){
    let alertController = UIAlertController(title: "Add New Name", message: "", preferredStyle: .alert)
    alertController.addTextField { (textField : UITextField!) -> Void in
        textField.placeholder = "Enter Second Name"
    }
    let saveAction = UIAlertAction(title: "Save", style: .default, handler: { alert -> Void in
        let firstTextField = alertController.textFields![0] as UITextField
        let secondTextField = alertController.textFields![1] as UITextField
        print("firstName \(firstTextField.text), secondName \(secondTextField.text)")
    })
    let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: { (action : UIAlertAction!) -> Void in })
    alertController.addTextField { (textField : UITextField!) -> Void in
        textField.placeholder = "Enter First Name"
    }

    alertController.addAction(saveAction)
    alertController.addAction(cancelAction)
    
    self.present(alertController, animated: true, completion: nil)
}

Para adicionar um campo de texto no Swift 3.0:

let alertController = UIAlertController(title: "Title", message: "", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "Save", style: .default, handler: { alert -> Void in
    let textField = alertController.textFields![0] as UITextField
    // do something with textField
}))
alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
alertController.addTextField(configurationHandler: {(textField : UITextField!) -> Void in
    textField.placeholder = "Search"
})   
self.present(alertController, animated: true, completion: nil)

Portanto, comecei a verificar o que poderia ter sido diferente em meu código para o código de trabalho. Percebi que meu ViewController estende

UITextFieldDelegate

O que aparentemente significa que preciso definir o delegado de qualquer UITextView filho:

alertController.addTextFieldWithConfigurationHandler { (textField) -> Void in
    searchTextField = textField
    searchTextField?.delegate = self //REQUIRED
    searchTextField?.placeholder = "Enter your search terms"
}

Solução:

Swift 4.2

Experimente as seguintes linhas e veja se funciona:

let alertController = UIAlertController(title: "Add New Name", message: "", preferredStyle: .alert)

alertController.addTextField { (textField : UITextField!) -> Void in
    textField.placeholder = "Enter Second Name"
}

let saveAction = UIAlertAction(title: "Save", style: .default, handler: { alert -> Void in
    let firstTextField = alertController.textFields![0] as UITextField
    let secondTextField = alertController.textFields![1] as UITextField
})

let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: nil )

alertController.addTextField { (textField : UITextField!) -> Void in
    textField.placeholder = "Enter First Name"
}

alertController.addAction(saveAction)
alertController.addAction(cancelAction)

self.present(alertController, animated: true, completion: nil)

Espero que ajude.

Como adicionar textField ao AlertView? Vamos ser curtos e simples.

Isso funciona para Swift 3.0 e superior.

var nameField: UITextField?
let alertController = UIAlertController(title: "Add Number", message: nil, preferredStyle: .alert)
// Add textfield to alert view
alertController.addTextField { (textField) in
    nameField = textField
}

Primeiro, você instancia um objeto de UIAlertControllere, em seguida, adiciona um campo de texto a ele acessando addTextFieldmembro da UIAlertControllerclasse.

Para adicionar alertController com um textField (Swift 5)

func openAlert(){
    let alertController = UIAlertController(title: "Title", message: "", preferredStyle: .alert)
    alertController.addTextField { (textField : UITextField!) -> Void in
        textField.placeholder = "Enter name"
    }

    let saveAction = UIAlertAction(title: kAlertConfirm, style: .default, handler: { alert -> Void in
        if let textField = alertController.textFields?[0] {
            if textField.text!.count > 0 {
                print("Text :: \(textField.text ?? "")")
            }
        }
    })

    let cancelAction = UIAlertAction(title: kAlertCancel, style: .default, handler: {
        (action : UIAlertAction!) -> Void in })

    alertController.addAction(cancelAction)
    alertController.addAction(saveAction)

    alertController.preferredAction = saveAction

    self.present(alertController, animated: true, completion: nil)
}

Para Swift 4.0, você pode usar este exemplo de código testado com sucesso em meu projeto:

@IBAction func withdrawTapped(_ sender: UIButton) {

  let alertController = UIAlertController(title: "Token withdraw", message: "", preferredStyle: .alert)

  let withdrawAction = UIAlertAction(title: "Withdraw", style: .default) { (aciton) in

    let text = alertController.textFields!.first!.text!

    if !text.isEmpty {
      self.presentAlert(
        title: "Succesful", 
        message: "You made request for withdraw \(textField.text) tokens")
    }
  }

  let cancelAction = UIAlertAction(title: "Cancel", style: .cancel) { (action) in
  }

  alertController.addTextField { (textField) in
    textField.placeholder = "999"
    textField.keyboardType = .decimalPad
  }

  alertController.addAction(withdrawAction)
  alertController.addAction(cancelAction)

  self.present(alertController, animated: true, completion: nil)
}

Em Swift 4.2 e Xcode 10.1

Alerte com dois Textfields e Leia dados de texto TextField e apresente o alerta na parte superior de todas as visualizações .

func alertWithTF(title: String, message: String) {
    //Step : 1
    let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)

    //Step : 2
    alert.addAction (UIAlertAction(title: "Save", style: .default) { (alertAction) in
        let textField = alert.textFields![0]
        let textField2 = alert.textFields![1]
        if textField.text != "" {
            //Read textfield data
            print(textField.text!)
            print("TF 1 : \(textField.text!)")
        } else {
            print("TF 1 is Empty...")
        }
        if textField2.text != "" {
            //Read textfield data
            print(textField2.text!)
            print("TF 2 : \(textField2.text!)")
        } else {
            print("TF 2 is Empty...")
        }
    })

    //Step : 3
    //For first TF
    alert.addTextField { (textField) in
        textField.placeholder = "Enter your first name"
        textField.textColor = .red
    }
    //For second TF
    alert.addTextField { (textField) in
        textField.placeholder = "Enter your last name"
        textField.textColor = .blue
    }

    //Cancel action
    alert.addAction(UIAlertAction(title: "Cancel", style: .default) { (alertAction) in })
   self.present(alert, animated:true, completion: nil)

}

Se você deseja apresentar aleert acima de todas as visualizações.

Aqui do código acima, remova esta última linha self.present(alert, animated:true, completion: nil)e adicione o código abaixo.

//Present alert on top of all views.
let alertWindow = UIWindow(frame: UIScreen.main.bounds)
alertWindow.rootViewController = UIViewController()
alertWindow.windowLevel = UIWindowLevelAlert + 1

alertWindow.makeKeyAndVisible()

alertWindow.rootViewController?.present(alert, animated:true, completion: nil)

Agora ligue assim

alertWithTF(title: "This is title", message: "This is message")

Ótima resposta, uma pequena modificação para mostrar como o campo de texto pode ser usado:

func addRow (row: Int, bodin: String, flag: Int) {
    let alertController = UIAlertController(title: bodin, message: "", preferredStyle: .alert)
    alertController.addAction(UIAlertAction(title: "Save", style: .default, handler: {
        alert -> Void in
        _ = alertController.textFields![0] as UITextField

    }))
    alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))

    alertController.addTextField(configurationHandler: {(textField : UITextField!) -> Void in
        switch flag {
        case 0:
            textField.keyboardType = UIKeyboardType.phonePad
            textField.placeholder = "Enter Number"
        case 1:
            textField.keyboardType = UIKeyboardType.emailAddress
            textField.placeholder = "Enter Email"
        default:
            break
        }

    })

adicione TextField a UIAlertController e TextField text Display em UILabel em Swift

let alert = UIAlertController(title: "Alert", message: "", preferredStyle: .alert)

alert.addTextField { (textField) in
textField.placeholder = "First Name"
}
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { [weak alert] (_) in
let textField = alert?.textFields![0]
self.label.text = textField?.text  }))

self.present(alert, animated: true, completion: nil)

UIAlertControllercom a versãoUITextfield mais recente do Apple Swift 5.1.3

Criar uma lazy variável de UIAlertControllerna sua UIViewController, adicione UITextFieldDelegate, alerta mostrar no UIButtonAção :

class  YourViewController: UIViewController,UITextFieldDelegate {

    //Create Alert Controller Object here
    lazy var alertEmailAddEditView:UIAlertController = {

        let alert = UIAlertController(title:"My App", message: "Customize Add/Edit Email Pop Up", preferredStyle:UIAlertController.Style.alert)

        //ADD TEXT FIELD (YOU CAN ADD MULTIPLE TEXTFILED AS WELL)
        alert.addTextField { (textField : UITextField!) in
            textField.placeholder = "Enter  emails"
            textField.delegate = self
        }

        //SAVE BUTTON
        let save = UIAlertAction(title: "Save", style: UIAlertAction.Style.default, handler: { saveAction -> Void in
            let textField = alert.textFields![0] as UITextField
            print("value entered by user in our textfield is: \(textField.text)")
        })
        //CANCEL BUTTON
        let cancel = UIAlertAction(title: "Cancel", style: UIAlertAction.Style.default, handler: {
            (action : UIAlertAction!) -> Void in })


        alert.addAction(save)
        alert.addAction(cancel)

        return alert
    }()


    //MARK:- UIButton Action for showing Alert Controller
    @objc func buttonClicked(btn:UIButton){
        self.present(alertEmailAddEditView, animated: true, completion: nil)
    }

    //MARK:- UITextFieldDelegate
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }
}

Happy Coding !! :)

Swift5

A primeira classe está em conformidade com UITextFieldDelegate e, em seguida, cria uma nova propriedade textField

    private var myTextField : UITextField?

    // now where u want to add code
    let alertContoller = UIAlertController.init(title: "Add", message: "My message to user", preferredStyle: .alert)
    alertContoller.addTextField { (textField) in
        // make sure your outside any property should be accessed with self here
        self.myTextField = textField
        //Important step assign textfield delegate to self
        self.myTextField?.delegate = self 
        self.myTextField?.placeholder = self.textFieldPlaceholderText
    }
    let action = UIAlertAction.init(title: "Ok", style: .default) { action in
        print("Alert tapped")
    }
    alertContoller.addAction(action)
    present(alertContoller, animated: true, completion:nil)

obrigado

private func showLoginAlert() {
    let loginAlert = UIAlertController(title: "Login Using Credentials", message: nil, preferredStyle: .alert)
    loginAlert.view.tintColor = .systemBlue

    loginAlert.addTextField { usernameField in
        usernameField.font = .systemFont(ofSize: 17.0)
        usernameField.placeholder = "Username"
    }
    loginAlert.addTextField { passwordField in
        passwordField.font = .systemFont(ofSize: 17.0)
        passwordField.isSecureTextEntry = true
        passwordField.placeholder = "Password"
    }

    let cancelAction = UIAlertAction(title: "Cancel",
                                     style: .destructive,
                                     handler: { _ in
                                        // self.handleUsernamePasswordCanceled(loginAlert: loginAlert)
    })
    loginAlert.addAction(cancelAction)

    let loginAction = UIAlertAction(title: "Login",
                                    style: .default,
                                    handler: { _ in
                                        // self.handleUsernamePasswordEntered(loginAlert: loginAlert)
    })
    loginAlert.addAction(loginAction)
    loginAlert.preferredAction = loginAction
    present(loginAlert, animated: true, completion: nil)
}

Swift 5