从 Swift 中的 iOS 警报中的 TextField 获取输入值

Get input value from TextField in iOS alert in Swift

提问by ntoonio

I'm trying to make an alert message with input, and then get the value from the input. I've found many good tutorials how to make the input text field. but I can't get the value from the alert.

我正在尝试使用输入制作警报消息，然后从输入中获取值。我发现了很多很好的教程如何制作输入文本字段。但我无法从警报中获取价值。

回答by Andy Ibanez

Updated for Swift 3 and above:

为 Swift 3 及更高版本更新：

//1. Create the alert controller.
let alert = UIAlertController(title: "Some Title", message: "Enter a text", preferredStyle: .alert)

//2. Add the text field. You can configure it however you need.
alert.addTextField { (textField) in
    textField.text = "Some default text"
}

// 3. Grab the value from the text field, and print it when the user clicks OK.
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { [weak alert] (_) in
    let textField = alert.textFields![0] // Force unwrapping because we know it exists.
    print("Text field: \(textField.text)")
}))

// 4. Present the alert.
self.present(alert, animated: true, completion: nil)

---

---

Swift 2.x

斯威夫特 2.x

Assuming you want an action alert on iOS:

假设您想要在 iOS 上的操作警报：

//1. Create the alert controller.            
var alert = UIAlertController(title: "Some Title", message: "Enter a text", preferredStyle: .Alert)

//2. Add the text field. You can configure it however you need.
alert.addTextFieldWithConfigurationHandler({ (textField) -> Void in
    textField.text = "Some default text."
})

//3. Grab the value from the text field, and print it when the user clicks OK. 
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { [weak alert] (action) -> Void in
    let textField = alert.textFields![0] as UITextField
    println("Text field: \(textField.text)")
}))

// 4. Present the alert.
self.presentViewController(alert, animated: true, completion: nil)

回答by Gunhan

Swift 3/4

斯威夫特 3/4

You can use the below extension for your convenience.

为方便起见，您可以使用以下扩展程序。

Usage inside a ViewController:

在 a 中的用法ViewController：

showInputDialog(title: "Add number",
                subtitle: "Please enter the new number below.",
                actionTitle: "Add",
                cancelTitle: "Cancel",
                inputPlaceholder: "New number",
                inputKeyboardType: .numberPad)
{ (input:String?) in
    print("The new number is \(input ?? "")")
}

The extension code:

扩展代码：

extension UIViewController {
    func showInputDialog(title:String? = nil,
                         subtitle:String? = nil,
                         actionTitle:String? = "Add",
                         cancelTitle:String? = "Cancel",
                         inputPlaceholder:String? = nil,
                         inputKeyboardType:UIKeyboardType = UIKeyboardType.default,
                         cancelHandler: ((UIAlertAction) -> Swift.Void)? = nil,
                         actionHandler: ((_ text: String?) -> Void)? = nil) {

        let alert = UIAlertController(title: title, message: subtitle, preferredStyle: .alert)
        alert.addTextField { (textField:UITextField) in
            textField.placeholder = inputPlaceholder
            textField.keyboardType = inputKeyboardType
        }
        alert.addAction(UIAlertAction(title: actionTitle, style: .default, handler: { (action:UIAlertAction) in
            guard let textField =  alert.textFields?.first else {
                actionHandler?(nil)
                return
            }
            actionHandler?(textField.text)
        }))
        alert.addAction(UIAlertAction(title: cancelTitle, style: .cancel, handler: cancelHandler))

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

回答by iOS

In Swift5ans Xcode 10

在Swift5和 Xcode 10 中

Add two textfields with Save and Cancel actions and read TextFields text data

添加两个带有保存和取消操作的文本字段并读取文本字段文本数据

func alertWithTF() {
    //Step : 1
    let alert = UIAlertController(title: "Great Title", message: "Please input something", preferredStyle: UIAlertController.Style.alert )
    //Step : 2
    let save = UIAlertAction(title: "Save", style: .default) { (alertAction) in
        let textField = alert.textFields![0] as UITextField
        let textField2 = alert.textFields![1] as UITextField
        if textField.text != "" {
            //Read TextFields text data
            print(textField.text!)
            print("TF 1 : \(textField.text!)")
        } else {
            print("TF 1 is Empty...")
        }

        if textField2.text != "" {
            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
    }

    //Step : 4
    alert.addAction(save)
    //Cancel action
    let cancel = UIAlertAction(title: "Cancel", style: .default) { (alertAction) in }
    alert.addAction(cancel)
    //OR single line action
    //alert.addAction(UIAlertAction(title: "Cancel", style: .default) { (alertAction) in })

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

}

For more explanation https://medium.com/@chan.henryk/alert-controller-with-text-field-in-swift-3-bda7ac06026c

更多解释https://medium.com/@chan.henryk/alert-controller-with-text-field-in-swift-3-bda7ac06026c