从基础遍历到所有后代的类层次结构 [英] Traverse a class hierarchy from base to all descendants
问题描述
在编写iOS应用程序时,我想遍历类层次结构以列出所有子类的清单.我的目的是在字典中通过NSStringForClass()
将每个子类类型用作键.
In an iOS app I am writing I want to traverse a class hierarchy to make an inventory of all subclasses. My intent is to use each subclass type as a key -- via NSStringForClass()
-- in a dictionary.
我的动机是能够自动发现基类的所有变体,以便我可以调用与该类关联的方法.出于分工的原因,我不想在此使用覆盖方法.
My motivation is to be able to automatically discover all variants of a base class so that I can call methods associated with that class. For reasons of division of labor I prefer not to use method overriding here.
是否可以进行这种遍历?它将如何工作?
Is it possible to do such a traversal? How would it work?
推荐答案
下面是一个示例.此方法将返回从您向其发送消息的类继承的所有子类.
Here's an example. This method will return all subclasses descending from the class you send the message to.
@interface NSObject (Debugging)
+ (NSArray *) allSubclasses;
@end
@implementation NSObject (Debugging)
+ (NSArray *) allSubclasses
{
Class myClass = [self class];
NSMutableArray *mySubclasses = [NSMutableArray array];
unsigned int numOfClasses;
Class *classes = objc_copyClassList(&numOfClasses);
for (unsigned int ci = 0; ci < numOfClasses; ci++) {
// Replace the code in this loop to limit the result to immediate subclasses:
// Class superClass = class_getSuperclass(classes[ci]);
// if (superClass == myClass)
// [mySubclasses addObject: classes[ci]];
Class superClass = classes[ci];
do {
superClass = class_getSuperclass(superClass);
} while (superClass && superClass != myClass);
if (superClass)
[mySubclasses addObject: classes[ci]];
}
free(classes);
return mySubclasses;
}
@end
根据需要进行修改,进行递归调用等.
Modify it as needed, make recursive calls, etc.
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