UICollectionView cell size - swift 3/4 - swift

Question

I am working on Collection view.I want to display 3 rows in collection view . Each row having two cells.The problems is i can't able to fit the cells in a row.Please kindly refer my code which i tried.
import UIKit
class ProductsTableViewCell: UITableViewCell {
#IBOutlet weak var productsCollections: UICollectionView!
override func awakeFromNib() {
super.awakeFromNib()
productsCollections.isScrollEnabled = false
productsCollections.dataSource = self as? UICollectionViewDataSource
productsCollections.delegate = self as? UICollectionViewDelegate
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
extension ProductsTableViewCell: UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 6
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Product", for: indexPath)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: 10, left: 10, bottom: 0, right: 10)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return collectionView.frame.width/9
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return collectionView.frame.width
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let collectionViewWidth = collectionView.bounds.width
let collectionViewHeight = collectionView.bounds.height
return CGSize(width: collectionViewWidth/2.0 , height: collectionViewHeight/2.5)
}
[This is the output i got.][1]}
I want like this.totally 6 rows.Per row 2 cells i want to display

Answer 1

First of all, calculate a row height that you need. So it is depends on screen resolution.
for example :
1- Declare a variable
fileprivate var cellHeight: CGFloat
2- calculate it once in viewDidLoad()
self.cellHeight = yourContainerFrameHeight / 3
3- Remove minimumLineSpacingForSectionAt
4- Calculate cell size.
I'm not sure, but you should not use the size of the CollectionView here (in sizeForItemAt). Instead you can use a fixed UIView or screen sizes. Because we already identify it.
This example has self.contentView you must change with yours or screen size
And try this:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
flowLayout.invalidateLayout()
let vMiddle = self.contentView.frame.size.width / 2.0
//this calculation for prevent next row shifts and fit rows
let cellWidth =
indexPath.row % 2 == 0 ? floor(vMiddle) : self.contentView.frame.size.width - floor(vMiddle)
//print("---------- cell width : \(cellWidth)")
return CGSize(width: cellWidth, height: self.cellHeight)
}