Couldn't get UISwipeGestureRecognizer direction correctly

Question

I'm writing code to move my two fingers up or down on a view to change some status. The code as below:

UISwipeGestureRecognizer *aSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
[aSwipeGesture setDirection:UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionDown];
aSwipeGesture.numberOfTouchesRequired = 2;
[self.View addGestureRecognizer:aSwipeGesture];


- (void)swipeGesture:(UISwipeGestureRecognizer *)sender {
    NSLog(@"Swipe received.");
    if (sender.direction==UISwipeGestureRecognizerDirectionUp) {
        NSLog(@"swipe up");
    } else if (sender.direction==UISwipeGestureRecognizerDirectionDown) {
        NSLog(@"swipe down");
    }
}

However the only print log I could receive was Swipe received as below shows. I couldn't get the message for swipe up or swipe down, did I miss anything? Thanks

ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.
ViewController.m:228    Swipe received.

Updated: I have to use two fingers to finish the swipe action.

Answer 1

Try this

UISwipeGestureRecognizer *aSwipeGestureUp = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
[aSwipeGesture setDirection:UISwipeGestureRecognizerDirectionUp];
aSwipeGestureUp.numberOfTouchesRequired = 2;
[self.View addGestureRecognizer:aSwipeGestureUp];

UISwipeGestureRecognizer *aSwipeGestureDown = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGesture:)];
[aSwipeGestureDown setDirection:UISwipeGestureRecognizerDirectionDown];
aSwipeGestureDown.numberOfTouchesRequired = 2;
[self.View addGestureRecognizer:aSwipeGestureDown];