UICollectionView won't center - ios

Question

I have a fullscreen UICollectionView with cells. I have checked the width and height, and the view covers the entire screen. However, when I enabled paging, the view was no longer centered. How can I set the center of the cell or the collection view, so it does take the entire screen?
import UIKit
class ShowPictures: UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
var PICTURES: [Picture] = []
#IBAction func swipeAway(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
}
override var prefersStatusBarHidden: Bool {
return true
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
private func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return UIScreen.main.bounds.size
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return self.PICTURES.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let item: Messages.MessageAdapter.Item.Picture = self.PICTURES[indexPath.section]
let cell: Cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! Cell
return cell
}
#IBAction func CloseController(_ sender: Any) {
dismiss(animated: true, completion: nil)
}
}
class Cell: UICollectionViewCell, UIScrollViewDelegate {
#IBOutlet weak var _image: UIImageView!
#IBOutlet weak var _scroll: UIScrollView!
override func layoutSubviews() {
self._scroll.delegate = self
self._scroll.zoomScale = CGFloat(integerLiteral: 1)
}
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return self._image
}
}

Answer 1

Add the following delegate method to remove the inset:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return .zero
}