关于UISwipeGestureRecognizerDirection问题

在viewDidLoad 中设置：

 UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeFrom:)];
    [swipeGesture setDirection:(UISwipeGestureRecognizerDirectionLeft | UISwipeGestureRecognizerDirectionRight)];
    [self.view addGestureRecognizer:swipeGesture];

-(void)handleSwipeFrom:(UISwipeGestureRecognizer *)recognizer {
    NSLog(@"Swipe received.");
    UISwipeGestureRecognizerDirection temp = recognizer.direction;
    if (recognizer.direction == UISwipeGestureRecognizerDirectionLeft)
    {
        [self backCalendarPressed:nil];
    }
    else if (recognizer.direction == UISwipeGestureRecognizerDirectionRight)
    {
        [self nextCalendarPressed:nil];
    }
}

但是recognizer.direction总是等于3，这样的结果我没有办法判断是向左滑动还是向右滑动。