I've this situation:
I programmatically create the cells (UIView) with label inside and correctly set contentSize of scrollView.
I know that
scrollView.setContentOffset(CGPoint(x: 0, y: 80.0), animated: true)
move scroll view by 80.
How can I "override" scroll view behaviour in order to always scroll by 80? What i want is sort of picker behaviour.. is this possible?
You can use the following method when your layout changes
func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
myScrollView.contentOffset.y += 80
}
No one answer correctly to the question, so I solved by my self as usually:
let viewHeight: CGFloat = 80.0
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
startContentOffsetY = scrollView.contentOffset.y
}
func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
targetContentOffsetY = targetContentOffset.memory.y
if startContentOffsetY - targetContentOffsetY < 0 {
scrollDirection = ScrollDirection.Bottom.rawValue
} else {
scrollDirection = ScrollDirection.Top.rawValue
}
let gap = targetContentOffsetY % viewHeight
var offset: CGFloat = 0.0
if (targetContentOffsetY - gap) % viewHeight == 0 {
offset = -gap * scrollDirection
} else {
offset = gap * scrollDirection
}
let newTarget = targetContentOffsetY + (offset * scrollDirection)
targetContentOffset.memory.y = newTarget
}
maybe something like this: (you need to add some validations) make a delegate class for your scroll view (UIScrollViewDelegate)
now add this function inside your UIScrollViewDelegate
myScrollView.delegate = instanceOfUIScrollViewDelegate;
func scrollViewDidScroll(scrollView: UIScrollView) {
scrollView.contentOffset.y+=80;
}
你可以使用这种方法
scrollView.setContentOffset( CGPoint(x:0,y:30), animated:true )
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