Question

我有一个UIAlertController，当他们在TouchID屏幕上选择“输入密码”时会提示用户。如何在屏幕上显示后恢复用户的输入？

let passwordPrompt = UIAlertController(title: "Enter Password", message: "You have selected to enter your passwod.", preferredStyle: UIAlertControllerStyle.Alert)
passwordPrompt.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Default, handler: nil))
passwordPrompt.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))

passwordPrompt.addTextFieldWithConfigurationHandler({(textField: UITextField!) in
                        textField.placeholder = "Password"
                        textField.secureTextEntry = true
                        })

presentViewController(passwordPrompt, animated: true, completion: nil)

我知道OK按钮应该有一个处理程序，但是现在这段代码并没有真正做任何事情，但我想通过println显示文本字段的输出。这对我来说只是一个测试应用程序，可以学习Swift和一些新的API。

Answer 1

我已经写了blog post来探索新的API。你可以在闭包中捕获一个局部变量，你就可以了。

var inputTextField: UITextField?
let passwordPrompt = UIAlertController(title: "Enter Password", message: "You have selected to enter your password.", preferredStyle: UIAlertControllerStyle.Alert)
passwordPrompt.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Default, handler: nil))
passwordPrompt.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: { (action) -> Void in
    // Now do whatever you want with inputTextField (remember to unwrap the optional)
}))
passwordPrompt.addTextFieldWithConfigurationHandler({(textField: UITextField!) in
    textField.placeholder = "Password"
    textField.secureTextEntry = true
    inputTextField = textField
 })

presentViewController(passwordPrompt, animated: true, completion: nil)

这样可以避免视图控制器上出现不必要的属性。

Answer 2

我知道已发布评论以回答问题，但答案应该使解决方案明确。

@IBOutlet var newWordField: UITextField
func wordEntered(alert: UIAlertAction!){
    // store the new word
    self.textView2.text = deletedString + " " + self.newWordField.text
}
func addTextField(textField: UITextField!){
    // add the text field and make the result global
    textField.placeholder = "Definition"
    self.newWordField = textField
}

// display an alert
let newWordPrompt = UIAlertController(title: "Enter definition", message: "Trainging the machine!", preferredStyle: UIAlertControllerStyle.Alert)
newWordPrompt.addTextFieldWithConfigurationHandler(addTextField)
newWordPrompt.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Default, handler: nil))
newWordPrompt.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: wordEntered))
presentViewController(newWordPrompt, animated: true, completion: nil)

这会显示一个带有文本字段和两个操作按钮的提示。它完成后会读取文本字段。

Answer 3

我将Ash Furrow's answer移植到Swift 3。

    var inputTextField: UITextField?
    let passwordPrompt = UIAlertController(title: "Enter Password", message: "You have selected to enter your password.", preferredStyle: UIAlertControllerStyle.alert)
    passwordPrompt.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.default, handler: nil))
    passwordPrompt.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: { (action) -> Void in
        // Now do whatever you want with inputTextField (remember to unwrap the optional)
    }))
    passwordPrompt.addTextField(configurationHandler: {(textField: UITextField!) in
        textField.placeholder = "Password"
        textField.isSecureTextEntry = true
        inputTextField = textField
    })

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

Answer 4

在封闭内容中执行此操作：

let tf = alert.textFields[0] as UITextField

Here is a gist

从UIAlertController访问输入

4 个答案: