如何检测同时手势的结束？ (IOS)

.h文件：

int handledGesturesCount;

.m文件：

- (id)init {
    (...)
    handledGesturesCount = 0;
}

// gesture handlers - the code for -pinch: repeats for -pan: and -rotate:
- (void)pinch:(UIPinchGestureRecognizer *)recognizer {
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        handledGesturesCount += 1;
    } else if (recognizer.state == UIGestureRecognizerStateEnded ||
               recognizer.state == UIGestureRecognizerStateCancelled ||
               recognizer.state == UIGestureRecognizerStateFailed)
    {
        handledGesturesCount -= 1;
        if (handledGesturesCount == 0) {
            [self resetImage];
        }
    }
}

- (void)pan:(UIPanGestureRecognizer *)recognizer {
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        handledGesturesCount += 1;
    } else if (recognizer.state == UIGestureRecognizerStateEnded ||
               recognizer.state == UIGestureRecognizerStateCancelled ||
               recognizer.state == UIGestureRecognizerStateFailed)
    {
        handledGesturesCount -= 1;
        if (handledGesturesCount == 0) {
            [self resetImage];
        }
    }
}

- (void)rotate:(UIRotationGestureRecognizer *)recognizer {
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        handledGesturesCount += 1;
    } else if (recognizer.state == UIGestureRecognizerStateEnded ||
               recognizer.state == UIGestureRecognizerStateCancelled ||
               recognizer.state == UIGestureRecognizerStateFailed)
    {
        handledGesturesCount -= 1;
        if (handledGesturesCount == 0) {
            [self resetImage];
        }
    }
}