Detect current page number in paging enabled Collection view

gistfile1.txt

    // Scrollview.tag will equal to your collection view's tag
    // Use page to update page control or whatever
    func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
        print("tag = \(scrollView.tag)")
        let pageWidth = scrollView.frame.size.width
        let page = Int(floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1)
        print("page = \(page)")
    }