arrays - Segue 不传输数组

Question

我似乎无法理解为什么每当我运行测试程序时数组答案都是空的。

当我在 View Controller 1 中使用 println(finalResultsSegue) 时，我可以看到结果数组，但是当我将其传递给 View Controller 2 中的答案时，它会转到下一个屏幕，但数组仍为空。

View Controller 1

@IBAction func submitAll(sender: UIButton) {

    let hasAnsweredAllQuestions = questions.reduce(true) { (x, q) in x && (q.usersAnswer != nil) }

    println("has user answered all questions?: \(hasAnsweredAllQuestions)")

    if hasAnsweredAllQuestions == true {

        for (index, _) in enumerate(questions) {
            userAnswers.append(questions[index].usersAnswer!)
            correctAnswers.append(questions[index].answer!)
        }
        if userAnswers.count == 3 {
                checkResults()
                }
            }
        }
    }

func checkResults() {
    let answer = map(zip(correctAnswers, userAnswers)){
        ($0.0 == $0.1) ? "correct" : "wrong"
    }
    var finalResults = answer.map({"The following answer is \($0)"})

    finalResultsSegue = finalResults

    println(finalResultsSegue)
}

@IBAction func nextPage(sender: AnyObject) {

    self.performSegueWithIdentifier("answerSummary", sender: sender)

    func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {

        if(segue.identifier == "answerSummary") {
            var answerSummary = segue.destinationViewController as! QuizResultsViewController

            answerSummary.answers = finalResultsSegue
        }
    }
}

View Controller 2

class QuizResultsViewController: UIViewController {

@IBOutlet weak var testLabel: UILabel!

var answers: [String] = []

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.

    println(answers)

}

Answer 1

您已将 prepareForSegue 作为 nextPage 内的嵌套函数。将其移到外面，它应该可以正常工作:

@IBAction func nextPage(sender: AnyObject) {
    self.performSegueWithIdentifier("answerSummary", sender: sender)
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
    if let answerSummary = segue.destinationViewController as? QuizResultsViewController
        where segue.identifier == "answerSummary"

        answerSummary.answers = finalResultsSegue
    }
}

事实上，您不必在 func prepareForSegue... 前面添加 override ，这暗示您已将 prepareForSegue 放入错误的地方。