我有以下型号:

class BaseClass { ... }
class WeakCollection<T: BaseClass> { ... }
class Person : BaseClass { ... }

class Parent : Person {
    var children: [Child]
    ...
}

class Child : Person {
    var parents: WeakCollection<Parent>
    ...
}

let aChild = Child()
...

我在用这样的反射:
let mirrored_object = Mirror(reflecting: aChild)
for attr in mirrored_object.children {
    switch attr.value {
         case is Int:
             ...

         case is String:
             ...

         case is WeakCollection<BaseClass>:
             ...
    }
}

问题是如果泛型类型不是case is WeakCollection<BaseClass>本身,即如果它是它的一些子类,那么BaseClass中的检查总是false。如何检查泛型类型?

最佳答案

这样做的一个粗略方法是,使您的“WeakCollection”继承某种协议:

protocol BaseProtocol {}
class WeakCollection<T> : BaseProtocol

然后在你的开关中这样做:
switch attr.value {
    case is String:
        // This is a string
        break
    case let optionalObject as Optional<Any>:
        if case .some(let complexObject) = optionalObject
        {
            if (complexObject is BaseProtocol)
            {
                // This is a "WeakCollection" kind
            }
        }
        break
}

这有点粗糙,但它给出了你想要的输出。

关于swift - Swift:如何在反射中检查泛型?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/42177861/

10-11 22:38
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