swift - 无法在 Swift 中访问多维数组

Question

我创建了一个多维数组，但当我尝试在 viewDidLoad 中访问它时，应用程序崩溃了。关于为什么会发生这种情况有什么建议吗？

我还尝试将我的数组定义为 var data: KeyLabelType[][]，但这也无济于事。

class MyViewController: UIViewController {

    var data: Array<Array<KeyLabelType>> = []

    init(nibName nibNameOrNil: String!, bundle nibBundleOrNil: NSBundle!)  {

        let array1: KeyLabelType[] = [...]
        let array2: KeyLabelType[] = [...]
        let array3: KeyLabelType[] = [...]

        self.data = [array1, array2, array3]

        super.init(nibName: nibNameOrNil, bundle: nibBundle)
    }

    override func viewDidLoad()  {

        let count = self.data.count // Application crashes here
    }
}

编辑:

我将 KeyLabelType 声明为

enum KeyLabelType: Character {
    case a = "a"
    case b = "b"
    case c = "c"
}

编辑:我向 Apple (17340589) 提交了错误报告

Answer 1

这是一个错误，请在 bugreport.apple.com 报告.这与在 swift 中子类化 NSObject 有一些关系。

import Foundation

enum KeyLabelType: Character {
    case a = "a"
    case b = "b"
    case c = "c"
}

class MyClass: NSObject /* Removing NSObject here will fix the crash */ {
    var myData: Array<Array<KeyLabelType>>

    init() {
        let array1: Array<KeyLabelType> = [.a, .b]
        let array2: Array<KeyLabelType> = [.b]
        let array3: Array<KeyLabelType> = [.c]

        self.myData = [array1, array2, array3]
    }
}

var myObject = MyClass()
myObject.myData //Crash here, if subclassing NSObject. No crash if NSObject is removed

如果您可以重写您的代码以一直使用 NSObject 子类，它也可以作为一种解决方法

import Foundation

class KeyLabelType: NSObject {
    let value: Int

    init(_ value: Int) {
        self.value = value
    }

}

class MyClass: NSObject {
    var myData: NSArray

    init() {
        var item = KeyLabelType(1)
        var array1: NSArray = [KeyLabelType(1), KeyLabelType(2)]
        var array2: NSArray = [KeyLabelType(1), KeyLabelType(2)]
        self.myData = [array1, array2]
    }
}

var myObject = MyClass()
myObject.myData.count