从 UIAlertView 文本字段获取文本的问题

Problems with getting text from UIAlertView textfield

在我的应用程序中,我想要一个带有文本字段的警报。单击 "Done" 后,我想将文本字段输入保存在一个字符串中。单击 "Cancel" 后,我只想关闭警报。我创建了这样的警报:

    var alert = UIAlertView()
    alert.title = "Enter Input"
    alert.addButtonWithTitle("Done")
    alert.alertViewStyle = UIAlertViewStyle.PlainTextInput
    alert.addButtonWithTitle("Cancel")
    alert.show()

    let textField = alert.textFieldAtIndex(0)
    textField!.placeholder = "Enter an Item"
    println(textField!.text)

警报看起来像这样:

我想知道如何从文本字段中获取文本,以及如何为 "Done" 按钮和 "Cancel" 按钮创建事件。

您将必须实施 UIAlertView Delegate 的

optional func alertView(_ alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int)

您可以使用 UIAlertController 而不是 UIAlertView。

我已经使用 UIAlertController 实现并测试了您的实际需求。请尝试以下代码

    var tField: UITextField!

    func configurationTextField(textField: UITextField!)
    {
        print("generating the TextField")
        textField.placeholder = "Enter an item"
        tField = textField
    }

    func handleCancel(alertView: UIAlertAction!)
    {
        print("Cancelled !!")
    }

    var alert = UIAlertController(title: "Enter Input", message: "", preferredStyle: .Alert)

    alert.addTextFieldWithConfigurationHandler(configurationTextField)
    alert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler:handleCancel))
    alert.addAction(UIAlertAction(title: "Done", style: .Default, handler:{ (UIAlertAction) in
        print("Done !!")

        print("Item : \(self.tField.text)")
    }))
    self.presentViewController(alert, animated: true, completion: {
        print("completion block")
    })

对于 iOS 8+,您应该使用 UIAlertController 而不是 UIAlertView。要支持 iOS 7 你应该实现 (UIAlertViewDelegate):

func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int)
{
    //...
    let textField = alertView.textFieldAtIndex(0)
}

对于SWIFT3

@IBAction func ForgotPassword(_ sender: Any) {

    let alertController = UIAlertController(title: "Email?", message: "Please input your email:", preferredStyle: .alert)

    let confirmAction = UIAlertAction(title: "Confirm", style: .default) { (_) in
        if let field = alertController.textFields![0] as? UITextField {

            // store and use entered data

        } else {

            print("please enter email id")
        }
    }

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

    alertController.addTextField { (textField) in
        textField.placeholder = "Email"
    }

    alertController.addAction(confirmAction)
    alertController.addAction(cancelAction)

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

}

希望对其他人有所帮助:)