如何在 Swift 中将 TextField 添加到 UIAlertController

Question

我正在尝试显示 UIAlertController 和 UITextView。当我添加行时：

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

我收到 Runtime 错误：

fatal error: unexpectedly found nil while unwrapping an Optional value

    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)

这是通过 IBAction 在我的 ViewController 中呈现的。

我已经从 here 下载了代码，它工作正常。我将该方法复制并粘贴到我的代码中，但它中断了。最后一行 self 的存在没有影响。

Answer 1

所以我开始检查我的代码与工作代码有什么不同。我注意到我的 ViewController 扩展了

UITextFieldDelegate

这显然意味着我需要设置任何子 UITextView 的委托：

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

Answer 2

Swift 5.1

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

使用此代码，我在我的应用程序中成功运行此代码。

@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)
}

已编辑：Swift 3.0 版本

@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)
}

Answer 3

要在 Swift 3.0 中添加文本字段：

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)

Answer 4

很好的回答，稍作修改以显示如何使用文本字段：

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
        }

    })

Answer 5

如何将textField添加到AlertView？让我们保持简短。

这适用于 Swift 3.0 及更高版本。

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

首先，您实例化 UIAlertController 的对象，然后通过访问 UIAlertController class 的 addTextField 成员向其添加文本字段。

Answer 6

在 Swift

中将 TextField 添加到 UIAlertController 并在 UILabel 上显示 TextField 文本

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)

Answer 7

对于 Swift 4.0，您可以使用在我的项目中成功测试的代码示例：

@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)
}

Answer 8

解法：

Swift 4.2

尝试以下几行，看看是否有效：

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)

希望对您有所帮助。

Answer 9

在 Swift 4.2 和 Xcode 10.1

使用两个文本字段发出警报和读取文本字段文本数据并且在所有视图顶部显示警报.

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)

}

如果您想在所有视图之上显示提示。

从上面的代码中删除最后一行 self.present(alert, animated:true, completion: nil) 并添加下面的代码。

//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)

现在这样调用

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

Answer 10

添加一个 textField 的 alertController (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)
}

Answer 11

Swift5

首先class 符合 UITextFieldDelegate ，然后创建新的 textField 属性

    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)

谢谢

Answer 12

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

Answer 13

UIAlertController UITextfield 最新 Apple Swift 版本 5.1.3

在您的 UIViewController 中创建 lazy 变量的 UIAlertController，添加 UITextFieldDelegate，在 [=17 上显示警报=] 动作 :

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
    }
}

编码愉快！！ :)

如何在 Swift 中将 TextField 添加到 UIAlertController

How to add TextField to UIAlertController in Swift

xcode

uitextfield

ios

swift

uialertcontroller

Swift 5.1