我可以返回一个类的所有子类的列表吗?例如:列出一个类的所有子类
class Mother {
}
class ChildFoo: Mother {
}
class ChildBar: Mother {
}
let motherSubclasses = ... // TODO
print(motherSubclasses) // should to return [ChildFoo.self, ChildBar.self]
我可以返回一个类的所有子类的列表吗?例如:列出一个类的所有子类
class Mother {
}
class ChildFoo: Mother {
}
class ChildBar: Mother {
}
let motherSubclasses = ... // TODO
print(motherSubclasses) // should to return [ChildFoo.self, ChildBar.self]
令人惊讶的是Objective-C的运行时函数只是工作以及与斯威夫特班,即使他们不从NSObject
子类。此外,Swift中的所有类似于从SwiftObject
派生。 SwiftObject
本身没有超类。
首先,包装结构来处理ObjC运行系统功能:
import Foundation
struct ClassInfo : CustomStringConvertible, Equatable {
let classObject: AnyClass
let className: String
init?(_ classObject: AnyClass?) {
guard classObject != nil else { return nil }
self.classObject = classObject!
let cName = class_getName(classObject)!
self.className = String(cString: cName)
}
var superclassInfo: ClassInfo? {
let superclassObject: AnyClass? = class_getSuperclass(self.classObject)
return ClassInfo(superclassObject)
}
var description: String {
return self.className
}
static func ==(lhs: ClassInfo, rhs: ClassInfo) -> Bool {
return lhs.className == rhs.className
}
}
这里是你如何使用它:
class Mother { }
class ChildFoo: Mother { }
class ChildBar: Mother { }
class AnIrrelevantClass { }
let motherClassInfo = ClassInfo(Mother.self)!
var subclassList = [ClassInfo]()
var count = UInt32(0)
let classList = objc_copyClassList(&count)!
for i in 0..<Int(count) {
if let classInfo = ClassInfo(classList[i]),
let superclassInfo = classInfo.superclassInfo,
superclassInfo == motherClassInfo
{
subclassList.append(classInfo)
}
}
print(subclassList)
这只能执行浅层搜索,所以它不会打扫孙子班,但你明白了。
我不相信如果不深入研究Obj-C运行时,这将是可能的 - [这个Q&A](http://stackoverflow.com/questions/7923586/objective-c-get-list-of-subclasses-从超类)可能会是一个很好的起点。虽然我会质疑*为什么*你确实想要这样做? – Hamish