oc消息转发

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self performSelector:@selector(foo)];
}

+ (BOOL)resolveInstanceMethod:(SEL)sel {
    return [super resolveInstanceMethod:sel];
}

- (id)forwardingTargetForSelector:(SEL)aSelector {
    // 指定转发对象
//    if(aSelector == @selector(foo)) {
//        return [Me new];
//    }
    return [super forwardingTargetForSelector:aSelector];
}

//
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {
    if (aSelector == @selector(foo)) {
        return [Me instanceMethodSignatureForSelector:aSelector];
    }
    return [super methodSignatureForSelector:aSelector];
}

- (void)forwardInvocation:(NSInvocation *)anInvocation {
    if (anInvocation.selector == @selector(foo)) {
        [anInvocation invokeWithTarget:[Me new]];
    } else {
        [super forwardInvocation:anInvocation];
    }
}

//- (void)doesNotRecognizeSelector:(SEL)aSelector {
//
//}


@end