How to connect UIPageControl to UICollectionView (Swift)

Firstly add your UIPageControl into your storyboard with your UICollectionView, then connect them as outlets to your view controller.

@IBOutlet var pageControl: UIPageControl!@IBOutlet var collectionView: UICollectionView!

Adjust your numberOfItemsInSection method in UICollectionViewDataSource to set the count of the page control to always be equal to the number of cells in the collection view.

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {    let count = ...    pageControl.numberOfPages = count    pageControl.isHidden = !(count > 1)    return count}

Lastly, using the UIScrollViewDelegate, we can tell which cell the UICollectionView stops on. If you are not using a UICollectionViewController, you may have to add the delegate protocol.

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {    pageControl?.currentPage = Int(scrollView.contentOffset.x) / Int(scrollView.frame.width)}func scrollViewDidEndScrollingAnimation(_ scrollView: UIScrollView) {    pageControl?.currentPage = Int(scrollView.contentOffset.x) / Int(scrollView.frame.width)}

This is possible because a UICollectionView is in fact a UIScrollView under the hood.

Step 1 Create the variables for Collection View and Page Control

@IBOutlet weak var collectionView: UICollectionView!@IBOutlet var pageControl:UIPageControl!     

Step 2 Set the number of pages of Page Control

override func viewDidLoad() {    super.viewDidLoad()             self.pageControl.numberOfPages = procedures.count    //Set the delegate    self.collectionView.delegate = self}

*Step 3 In the scrollViewDidScroll function calculate the width of collection cell and the index for the current page.

    extension YourCollectionVC: UICollectionViewDataSource, UICollectionViewDelegate {            override func scrollViewDidScroll(_ scrollView: UIScrollView) {                let witdh = scrollView.frame.width - (scrollView.contentInset.left*2)                let index = scrollView.contentOffset.x / witdh                let roundedIndex = round(index)                self.pageControl?.currentPage = Int(roundedIndex)            }}

Note: This is for collection view displayed horizontally, for vertical direccion change the method.

Tested in swift 4.

Use this for smooth functioning.

 func scrollViewDidScroll(_ scrollView: UIScrollView) {    let witdh = scrollView.frame.width - (scrollView.contentInset.left*2)    let index = scrollView.contentOffset.x / witdh    let roundedIndex = round(index)    self.pageControl.currentPage = Int(roundedIndex)}func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {    pageControl.currentPage = Int(scrollView.contentOffset.x) / Int(scrollView.frame.width)}func scrollViewDidEndScrollingAnimation(_ scrollView: UIScrollView) {    pageControl.currentPage = Int(scrollView.contentOffset.x) / Int(scrollView.frame.width)}