在Obj-C中发现给定类的子类

#import<Foundation/Foundation.h>
#import <objc/runtime.h>

void printSubclassesOfClass(Class parentClass) {
    unsigned int numClasses;
    Class *classes = NULL;
    classes = (__bridge Class *)objc_getClassList(NULL, &numClasses);

    for (int i = 0; i < numClasses; i++) {
        Class currentClass = classes[i];
        Class superclass = class_getSuperclass(currentClass);
        if (superclass == parentClass) {
            NSLog(@"%@", NSStringFromClass(currentClass));
        }
    }
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Class parentClass = NSObject.class;
        NSLog(@"Subclasses of %@:", NSStringFromClass(parentClass));
        printSubclassesOfClass(parentClass);
    }
    return 0;
}