ios - swift:我可以拥有一个实际上是引用的属性吗？

Question

例如..我想在它的初始化器中将一些字典传递给一个类，我想在我的类中引用这些字典..问题是当我将它们设置为属性时，它们实际上是被复制的，而不是引用。

例子:

var activeDict: [Int: Projectile]
var inactiveDict: [Int: Projectile]

init(inout activeDict: [Int: Projectile], inout inactiveDict: [Int: Projectile]) {
    self.activeDict = activeDict
    self.inactiveDict = inactiveDict

我想在我的类里面使用 activeDict 和 inactiveDict。我希望它们成为正在传递的原件的引用。

Answer 1

您可以将 UnsafeMutablePointer 存储到字典中，这是一个在 Playground 上测试过的示例:

var dict = ["hejj": 1]

class A<T> {
    var myDictRef: UnsafeMutablePointer<T>

    init(ref: UnsafeMutablePointer<T>) {
        self.myDictRef = ref
    }
}

let a = A(ref: &dict)
a.myDictRef.memory["asd"] = 3
a.myDictRef.memory
dict

已更新

在你的情况下使用它:

var activeDict: UnsafeMutablePointer<[Int: Projectile]>
var inactiveDict: UnsafeMutablePointer<[Int: Projectile]>

init(activeDict: UnsafeMutablePointer<[Int: Projectile]>, inactiveDict: UnsafeMutablePointer<[Int: Projectile]>) {
    self.activeDict = activeDict
    self.inactiveDict = inactiveDict
}

无论何时你想使用 activeDict 或 inactiveDict，你都可以调用指针后面的字典，它们的内存属性如下:

activeDict.memory[YourKey] = YourValue