Ios 错误：“找不到支持键盘类型4的键盘平面”

在这一行代码中：

if diceRoll == userGuessTextField.text {

我得到这个错误：

2016-02-04 18:38:34.756 How Many Fingers[2972:158461] Can't find keyplane that supports type 4 for keyboard iPhone-PortraitChoco-NumberPad; using 1336863583_PortraitChoco_iPhone-Simple-Pad_Default
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb) 

这是我的密码：

import UIKit

class ViewController: UIViewController {

    @IBOutlet var userGuessTextField: UITextField!

    @IBOutlet var resultLabel: UILabel!

    @IBAction func guess(sender: AnyObject) {

    let diceRoll = String(arc4random_uniform(6))


        if diceRoll == userGuessTextField.text {


            resultLabel.text = "You're right!"
        }
        else {

            resultLabel.text = "Wrong! It was a " + diceRoll
        }
    }


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

---

这只是一个警告，说明键盘类型不存在，很可能已弃用

另一方面，这是一个错误，很可能是因为userGuessTextField.text为零，无法进行比较

---

这里的解决方案是检查userGuessTextField.text是否有值，并且正如beyowulf所建议的，您应该将userGuessTextField连接到它的故事板元素。

Your@IBOutlet var userGuessTextField:UITextField！未连接到IB中的文本字段。请从其旁边的灰色空圆圈拖动到要成为UserGuestTextField的文本字段。

2016-02-04 18:38:34.756 How Many Fingers[2972:158461] Can't find keyplane that supports type 4 for keyboard iPhone-PortraitChoco-NumberPad; using 1336863583_PortraitChoco_iPhone-Simple-Pad_Default

fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb)