I want to display a NSCollectionLayoutItem occupy the device screen horizontally , and still get the correct aspect ratio in Vertical .

So I use the NSCollectionLayoutDimension.estimated(50) points for height . but after the image is downloaded , the height is still 50 ,which is not enough for display the image .

How to make the layout automatically fit the image’s content.

the image link is here : image src

and the result will be like this

the UICollectionView configuration code :

import UIKit

class ViewController: UIViewController {
    enum Section {
        case main
    }
    
    @IBOutlet weak var collectionView: UICollectionView!
    var dataSource: UICollectionViewDiffableDataSource<Section, Int>! = nil
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        self.configDataSource()
        self.configLayout()
    }

    
    func configDataSource() {
        let imageCellReg = UICollectionView.CellRegistration<ImageCell,Int>(cellNib: UINib(nibName: "ImageCell", bundle: nil)) { cell, indexPath, itemIdentifier in
            
        }
        self.dataSource = UICollectionViewDiffableDataSource<Section, Int>(collectionView: self.collectionView, cellProvider: { collectionView, indexPath, itemIdentifier in
            return self.collectionView.dequeueConfiguredReusableCell(using: imageCellReg, for: indexPath, item: itemIdentifier)
        })
        
        var snapshot = NSDiffableDataSourceSnapshot<Section, Int>()
        snapshot.appendSections([.main])
        snapshot.appendItems(Array(0..<2))
        dataSource.apply(snapshot, animatingDifferences: false)

    }
    
    func configLayout(){
        let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
                                             heightDimension: .fractionalHeight(1.0))
        let item = NSCollectionLayoutItem(layoutSize: itemSize)

        let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
                                               heightDimension:.estimated(50))
        let group = NSCollectionLayoutGroup.horizontal(layoutSize:groupSize, subitems: [item])
        let spacing = CGFloat(10)
        group.interItemSpacing = .fixed(spacing)

        let section = NSCollectionLayoutSection(group: group)
        section.interGroupSpacing = spacing
        section.contentInsets = NSDirectionalEdgeInsets(top: 0, leading: 10, bottom: 0, trailing: 10)

        let layout = UICollectionViewCompositionalLayout(section: section)
        self.collectionView.collectionViewLayout = layout
    }

}

And the cell code:

import UIKit
import SDWebImage

class ImageCell: UICollectionViewCell {
    @IBOutlet weak var imageContentView: UIImageView!
    
    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
        imageContentView.sd_setImage(with: URL(string: "https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png"))
    }

}