UIScrollView: paging horizontally, scrolling vertically?

Question

How can I force a UIScrollView in which paging and scrolling are on to only move vertically or horizontally at a given moment?

My understanding is that

Answer 1

For those looking in Swift at @AndreyTarantsov second solution its like this in code:

    var positionScroll:CGFloat = 0

    func scrollViewWillBeginDragging(scrollView: UIScrollView) {
        positionScroll = self.theScroll.contentOffset.x
    }

    func scrollViewDidScroll(scrollView: UIScrollView) {
        if self.theScroll.contentOffset.x > self.positionScroll || self.theScroll.contentOffset.x < self.positionScroll{
             self.theScroll.pagingEnabled = true
        }else{
            self.theScroll.pagingEnabled = false
        }
    }

what we are doing here is to keep the current position just before scrollview gets dragged and then check if either x has increased or decreased compared to the current position of x. If yes, then set the pagingEnabled to true, if no (y has increased/decreased) then set to pagingEnabled to false

Hope that is useful to new comers!