问题
How can I find out, at runtime, if a class overrides a method of its superclass?
For example, I want to find out if a class has it's own implementation of isEqual: or hash, instead of relying on a super class.
回答1:
You just need to get a list of the methods, and look for the one you want:
#import <objc/runtime.h>
BOOL hasMethod(Class cls, SEL sel) {
unsigned int methodCount;
Method *methods = class_copyMethodList(cls, &methodCount);
BOOL result = NO;
for (unsigned int i = 0; i < methodCount; ++i) {
if (method_getName(methods[i]) == sel) {
result = YES;
break;
}
}
free(methods);
return result;
}
class_copyMethodList only returns methods that are defined directly on the class in question, not superclasses, so that should be what you mean.
If you need class methods, then use class_copyMethodList(object_getClass(cls), &count).
来源：https://stackoverflow.com/questions/29809308/find-out-if-an-objective-c-class-overrides-a-method