iOS6 UICollectionView and UIPageControl – How to get visible cell?

You must setup yourself as UIScrollViewDelegate and implement the scrollViewDidEndDecelerating:method like so:

Objective-C

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    CGFloat pageWidth = self.collectionView.frame.size.width;
    self.pageControl.currentPage = self.collectionView.contentOffset.x / pageWidth;
}

Swift

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {

    let pageWidth = self.collectionView.frame.size.width
    pageControl.currentPage = Int(self.collectionView.contentOffset.x / pageWidth)
}