> @interface CustomObject : NSObject { id target; SEL selector; } - (void)setDelegate:(id)aTarget selector:(SEL)aSelector; - (void)setDelegate:(id)aTarget selector:(SEL)aSelector { self.target = aTarget; self.selector = aSelector; } // 콜백 메소드를 호출함 if(target) { [target performSelector:selector withObject:result_obj]; } ... > [custom_obj setDelegate:self Selector:@selector(CallBackMethod:)]; - (vo..