How to show two columns in a CollectionView using swift4 in all devices

Question

To show only two columns in a collectionView i am using this piece of code

    let layout = self.collectionView.collectionViewLayout as! UICollectionViewFlowLayout
    layout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0)
    layout.minimumInteritemSpacing = 4
    layout.itemSize = CGSize(width:(self.collectionView.frame.size.width - 10)/2,height: (self.collectionView.frame.size.height)/3)

but it is only showing properly on 5s, not on every iphone. please help.

i want to show my view controller like this image. please help anyone

Answer 1

You must be missing UICollectionViewDelegateFlowLayout

Try this and see:

// Source code
import UIKit

class CollectionVC: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {

    @IBOutlet var collection: UICollectionView!
    override func viewDidLoad() {
        super.viewDidLoad()
        collection.delegate = self
        collection.dataSource = self
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        //collection.reloadData()
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let flowayout = collectionViewLayout as? UICollectionViewFlowLayout
        let space: CGFloat = (flowayout?.minimumInteritemSpacing ?? 0.0) + (flowayout?.sectionInset.left ?? 0.0) + (flowayout?.sectionInset.right ?? 0.0)
        let size:CGFloat = (collection.frame.size.width - space) / 2.0
        return CGSize(width: size, height: size)
    }


    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 50
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "testcell", for: indexPath)
        cell.backgroundColor = UIColor.red
        return cell
    }

}

// Interface Design

Result:

Answer 2

Make sure your protocol confirms to your ViewController ,

class ViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout

And set flow layout to your collectionview object

In viewDidLoad

let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .vertical //.horizontal
layout.minimumLineSpacing = 5
layout.minimumInteritemSpacing = 5
collectionView.setCollectionViewLayout(layout, animated: true)

And implement following methods

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    return UIEdgeInsets(top: 1.0, left: 1.0, bottom: 1.0, right: 1.0)//here your custom value for spacing
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let lay = collectionViewLayout as! UICollectionViewFlowLayout
    let widthPerItem = collectionView.frame.width / 2 - lay.minimumInteritemSpacing
    
    return CGSize(width:widthPerItem, height:100)
}

Answer 3

add this code to viewDidLoad . change height according to you.

try this!

if let layout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout{
        layout.minimumLineSpacing = 10
        layout.minimumInteritemSpacing = 10
        layout.sectionInset = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)
        let size = CGSize(width:(collectionView!.bounds.width-30)/2, height: 250)
        layout.itemSize = size
}

Answer 4

I have following code which I have implemented to display two column in collection view.

Add UICollectionViewDelegateFlowLayout 's following method method:

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let size = (collectionView.frame.size.width - 30) / 2
    return CGSize(width: size, height: size)
}

Where 30 stand for left, right and middle space between cell.

ie Cell should be add 10 pixel on left Side, 10 pixel on right side and 10 pixel in between two cell.

Select you collectionview from storyboard and from Size Inspector set following minimum spacing.

I hope this will fix you issue.

Let me know if any query.

Answer 5

Update for Swift 5 and XCode 12.4

    import UIKit

class TwoColumnViewController: UIViewController {

    enum Section {
        case main
    }

    var dataSource: UICollectionViewDiffableDataSource<Section, Int>! = nil
    var collectionView: UICollectionView! = nil

    override func viewDidLoad() {
        super.viewDidLoad()
        navigationItem.title = "Two-Column Grid"
        configureHierarchy()
        configureDataSource()
    }
}

extension TwoColumnViewController {
    /// - Tag: TwoColumn
    func createLayout() -> UICollectionViewLayout {
        let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
                                             heightDimension: .fractionalHeight(1.0))
        let item = NSCollectionLayoutItem(layoutSize: itemSize)

        let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0),
                                              heightDimension: .absolute(44))
        let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitem: item, count: 2)
        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)
        return layout
    }
}

extension TwoColumnViewController {
    func configureHierarchy() {
        collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout())
        collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        collectionView.backgroundColor = .systemBackground
        view.addSubview(collectionView)
    }
    func configureDataSource() {
        let cellRegistration = UICollectionView.CellRegistration<TextCell, Int> { (cell, indexPath, identifier) in
            // Populate the cell with our item description.
            cell.label.text = "\(identifier)"
            cell.contentView.backgroundColor = .cornflowerBlue
            cell.layer.borderColor = UIColor.black.cgColor
            cell.layer.borderWidth = 1
            cell.label.textAlignment = .center
            cell.label.font = UIFont.preferredFont(forTextStyle: .title1)
        }
        
        dataSource = UICollectionViewDiffableDataSource<Section, Int>(collectionView: collectionView) {
            (collectionView: UICollectionView, indexPath: IndexPath, identifier: Int) -> UICollectionViewCell? in
            // Return the cell.
            return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: identifier)
        }

        // initial data
        var snapshot = NSDiffableDataSourceSnapshot<Section, Int>()
        snapshot.appendSections([.main])
        snapshot.appendItems(Array(0..<94))
        dataSource.apply(snapshot, animatingDifferences: false)
    }
}