I made a class GalleryCollectionViewController that inherited from UICollectionView like this:
import UIKit
class GalleryCollectionViewController: UICollectionViewController {
var dataSourceArr:Array<UIImage>!
override convenience init(collectionViewLayout layout: UICollectionViewLayout) {
self.init()
collectionView?.collectionViewLayout = layout
collectionView!.register(GalleryCollectionViewCell.self, forCellWithReuseIdentifier: "cell")
}
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: UICollectionViewDataSource
override func numberOfSections(in collectionView: UICollectionView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of items
if dataSourceArr.count != 0 {
return dataSourceArr.count
}
return 0
}
override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! GalleryCollectionViewCell
cell.imageView.image = dataSourceArr[indexPath.row]
return cell
}
GalleryCollectionViewCell has defined.
And in root controller set this in viewDidLoad :
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.sectionInset = UIEdgeInsets(top: 20, left: 10, bottom: 10, right: 10)
layout.itemSize = CGSize(width: 90, height: 120)
let galleryColVC = GalleryCollectionViewController(collectionViewLayout: layout)
galleryColVC.dataSourceArr = photoLibraryImagesArr
self.present(galleryColVC, animated: true, completion: nil)
And but get this error in UICollectionView :
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'UICollectionView must be initialized with a non-nil layout parameter'
Please help to fix this.