问如何像我的价值观一样获得随机化的钥匙？

EN

class QuestionDetails {
    let QADictionary = [
        "Who is Thor's brother?" : ["Atum", "Loki", "Red Norvell", "Kevin Masterson"],
        "What is the name of Thor's hammer?" : ["Mjolinr", "Uru", "Stormbreaker", "Thundara"],
        "Who is the father of Thor?" : ["Odin", "Sif", "Heimdall", "Balder"]
    ]

    //get question list
    func questionWithAnswers() {

        let listQuestions = QuestionDetails()

        var questionList = Array(listQuestions.QADictionary.keys)

        //random question index
        var rand = Int(arc4random_uniform(UInt32(questionList.count)))

        let randAnswers = rand

        //random answer index
        var answerList = Array(listQuestions.QADictionary.values)

        var choices = answerList[randAnswers]

        //fetch questions from list
        var question = questionList[rand]

        questionLabel.text = question

        //function for new question and button titles
        rightAnswerBox = arc4random_uniform(4)+1

        //create button
        var button:UIButton = UIButton()
        var x = 1

        for index in 1...4
        {
            button = view.viewWithTag(index) as! UIButton

            if (index == Int(rightAnswerBox))
            {
                button.setTitle(choices[0], for: .normal)
            }
            else {
                button.setTitle(choices[x], for: .normal)
                x += 1
            }

            randomImage()
        }
    }

    //variables
    var currentQuestion = 0
    var rightAnswerBox:UInt32 = 0
    var index = 0

    //Question Label
    @IBOutlet weak var questionLabel: UILabel!

    //Answer Button
    @IBAction func buttonAction(_ sender: AnyObject) {

        if (sender.tag == Int(rightAnswerBox)) {

            //removes asked question

            print ("Correct!")
        }
        else {
            wrongSeg()
            print ("Wrong!")
        }
    }

    override func viewDidAppear(_ animated: Bool) {
        questionWithAnswers()
    }
}