Is there a way to detect or get a notification when user changes the page in a paging-enabled UIScrollView?
Use this to detect which page is currently being shown and perform some action on page change:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
static NSInteger previousPage = 0;
CGFloat pageWidth = scrollView.frame.size.width;
float fractionalPage = scrollView.contentOffset.x / pageWidth;
NSInteger page = lround(fractionalPage);
if (previousPage != page) {
// Page has changed, do your thing!
// ...
// Finally, update previous page
previousPage = page;
}
}
If it's acceptable for you to only react to the page change once the scrolling has completely stopped, then it would be best to do the above inside the scrollViewDidEndDecelerating:
delegate method instead of the scrollViewDidScroll:
method.