[英]Swift: How to check for generic type in a reflection?
我有以下型號:
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()
...
我正在使用這樣的反射:
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>:
...
}
}
問題是在case is WeakCollection<BaseClass>
的檢查總是假如果泛型類型不是直接BaseClass
本身,也就是說,如果它是它的一些子類,則此檢查將是假的。 如何檢查泛型類型?
一個粗略的方法是讓你的“WeakCollection”從某種協議繼承:
protocol BaseProtocol {}
class WeakCollection<T> : BaseProtocol
然后在您的交換機中這樣做:
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
}
這有點粗糙,但它給出了你想要的輸出。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.