Question

为什么这不起作用？

我试图将字典值赋值为false的错误是它失败的地方。它返回此错误“致命错误：数组索引超出范围”，如底部输出中所示。

var tupleCount = 0
for var i = 0; i < width; ++i {
    for var j = 0; j < height; ++j {

        arrayOfTupleClass.append(TupleClass(newX: i, newY: j, newXMax: width, newYMax: height))

        print("arrayOfTupleClass.count: \(arrayOfTupleClass.count)")
        print("arrayOfTupleClass[tupleCount]: \(arrayOfTupleClass[tupleCount])")
        print("tupleCount: \(tupleCount)")
        print("imageNum: \(imageNum)")

        // placing '0' in place of dictionary Array index for simplicity
        pointDictionaryArray[0][arrayOfTupleClass[tupleCount]] = false // <-- error here

        tupleCount++
    }
}

这就是我的词典数组的设置方式：

var arrayOfTupleClass = [TupleClass]()
var pointDictionaryArray = [[TupleClass: Bool]]()

这是我的TupleClass，它应该包含一个类作为字典的键，因为我使它可以删除。

class TupleClass: Hashable {
    var x: Int!
    var y: Int!
    let yMax: Int!
    let xMax: Int!

    var weight: Int = 0

    init(newX: Int, newY: Int, newXMax: Int, newYMax: Int) {
        x = newX
        y = newY
        yMax = newYMax
        xMax = newXMax
    }

    func setWeight(newWeight: Int) {
        weight = newWeight
    }

    func getWeight() -> Int {
        return weight
    }

    // required for the Hashable protocol
    var hashValue: Int {
        return x * yMax + y
    }
};

// required function for the Equatable protocol, which Hashable inheirits from
func ==(left: TupleClass, right: TupleClass) -> Bool {
    return (left.x == right.x) && (left.y == right.y)
}

这是输出：

arrayOfTupleClass.count: 1
arrayOfTupleClass[tupleCount]: My_Project_Name.TupleClass
tupleCount: 0
imageNum: 0
fatal error: Array index out of range

Answer 1

据我所知，你不能使用swift Class Name作为参考（在较新的版本中也不能使用Obj-C）。但是，现在为什么要参考

    let myclassName = self.className
    let anotherClassName = NSClassFromString(self.classForCoder)

我刚刚把一个快速的游乐场示例打成了玩具：

import Foundation

debugPrint("Hello, World, Here we go from the PLayground template!")

let width = 100 // from your code
let height = 100 // from yoru code

typealias theTup = (newX: CGFloat, newY: CGFloat, newXMax: CGFloat,     newYMax: CGFloat) // setting a typ alias to your tuple format


var theTupArray: [theTup] /*Strong typing*/  = [theTup]() // lets make a new array (with default zero element value)

// lets add some default values for testing, nothing special
theTupArray.appendContentsOf([
    (newX: 1.0, newY: 2.0, newXMax: 2.0, newYMax: 5.0),
    (newX: 2.0, newY: 3.0, newXMax: 4.0, newYMax: 10.0),
    (newX: 3.0, newY: 4.0, newXMax: 6.0, newYMax: 15.0),
    ]
)

// now for-each element in the `theTupArray`... See Swift .forEach.. Or other shorthand methods like .map etc...

theTupArray.forEach { (
    newX: CGFloat,
    newY: CGFloat,
    newXMax: CGFloat,
    newYMax: CGFloat) in

    debugPrint("NewX 1:\(newX), NewY: \(newY), NewXMax: \(newXMax), NewYMax: \(newYMax)", terminator: "\n")

}

希望这种快速重写有助于：）

使用类作为键，在一组字典中索引超出范围 - 快速

1 个答案: