How to detect that UIScrollView is scrolling or that is is dragging

Question

I need to know on a continuous basis when my UIScrollView is scrolling or dragging.

Answer 1

Implement these two delegate methods..

- (void)scrollViewDidScroll:(UIScrollView *)sender{
  //executes when you scroll the scrollView
}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
 // execute when you drag the scrollView
}

Answer 2

Better use isTracking to detect if the user initiated a touch-drag.

func scrollViewDidScroll(_ scrollView: UIScrollView) {

    if scrollView.isTracking {   
    // ... 
    }
}