错误：＆＃34;无法找到支持键盘类型4的键盘＆＃34;

Question

在这行代码上：

if diceRoll == userGuessTextField.text {

我收到此错误：

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) 

这是我的代码：

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.
    }

Answer 1

这只是一个警告，键盘类型不存在，很可能已弃用。

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

另一方面，这是一个错误，很可能是因为userGuessTextField.text是nil并且无法进行比较。

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

此处的解决方案是检查userGuessTextField.text是否有值，并建议 beyowulf ，您应该将userGuessTextField连接到其storyboard元素。