Как заставить UISwipeGestureRecognizer И UIPanGestureRecognizer работать с одним и тем же представлением

Взгляните на эту статью Rico Mariani. Он дает два правила, когда назвать GC.Collect (правило 1: "Не делайте"):

, Когда назвать GC.Collect ()

24
задан Shizam 24 February 2011 в 23:24
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1 ответ

Использование распознавателя панорамирования для обнаружения перелистывания и панорамирования :

- (void)setupRecognizer
{
    UIPanGestureRecognizer* panSwipeRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanSwipe:)];
    // Here you can customize for example the minimum and maximum number of fingers required
    panSwipeRecognizer.minimumNumberOfTouches = 2;
    [targetView addGestureRecognizer:panSwipeRecognizer];
}

#define SWIPE_UP_THRESHOLD -1000.0f
#define SWIPE_DOWN_THRESHOLD 1000.0f
#define SWIPE_LEFT_THRESHOLD -1000.0f
#define SWIPE_RIGHT_THRESHOLD 1000.0f

- (void)handlePanSwipe:(UIPanGestureRecognizer*)recognizer
{
    // Get the translation in the view
    CGPoint t = [recognizer translationInView:recognizer.view];
    [recognizer setTranslation:CGPointZero inView:recognizer.view];

    // TODO: Here, you should translate your target view using this translation
    someView.center = CGPointMake(someView.center.x + t.x, someView.center.y + t.y);

    // But also, detect the swipe gesture
    if (recognizer.state == UIGestureRecognizerStateEnded)
    {
        CGPoint vel = [recognizer velocityInView:recognizer.view];

        if (vel.x < SWIPE_LEFT_THRESHOLD)
        {
            // TODO: Detected a swipe to the left
        }
        else if (vel.x > SWIPE_RIGHT_THRESHOLD)
        {
            // TODO: Detected a swipe to the right
        }
        else if (vel.y < SWIPE_UP_THRESHOLD)
        {
            // TODO: Detected a swipe up
        }
        else if (vel.y > SWIPE_DOWN_THRESHOLD)
        {
            // TODO: Detected a swipe down
        }
        else
        {
            // TODO:
            // Here, the user lifted the finger/fingers but didn't swipe.
            // If you need you can implement a snapping behaviour, where based on the location of your         targetView,
            // you focus back on the targetView or on some next view.
            // It's your call
        }
    }
}
5
ответ дан 28 November 2019 в 22:41
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