如何从具有同名嵌套类型的 class 中引用全局类型？

Question

我有一个在全局范围声明的 class 和另一个嵌套在某些 class 中的同名 class。

class Address {
    var someProperty: String?
}

class ThirdPartyAPI {
    class Address {
        var someOtherProperty: String?
        init(fromAddress address: Address) {
            self.someOtherProperty = address.someProperty
        }
    }
}

问题是：如何从其初始化程序中引用全局 class 而不是内部的？在给出的示例中，我遇到了一个错误 Value of type 'ThirdPartyAPI.Address' has no member 'someProperty'，这意味着编译器引用了内部 Address 而不是全局的。

Answer 1

使用typealias

class Address {
    var someProperty: String?
}

typealias GlobalAddress = Address

class ThirdPartyAPI {
    class Address {
        var someOtherProperty: String?
        init(fromAddress address: GlobalAddress) {
            self.someOtherProperty = address.someProperty
        }
    }
}

Answer 2

您可以通过在模块名称前加上唯一的方式来引用类型。所以如果

class Address {
    var someProperty: String?
}

在 "MySuperApp" 中定义，那么您可以将其称为 MySuperApp.Address:

class ThirdPartyAPI {

    class Address {
        var someOtherProperty: String?
        init(fromAddress address: MySuperApp.Address) {
            self.someOtherProperty = address.someProperty
        }
    }
}

(但如果你有选择，那么尽量避免歧义你的代码更容易理解。）

如何从具有同名嵌套类型的 class 中引用全局类型？

How to refer to a global type from within a class that has a nested type with the same name?

swift

scope

swift2

nested-class

scoping