Remove spacing in CollectionView iOS - swift

Question

I am using UICollectionViewDelegateFlowLayout delegate to make it square but strange spacing is showing at the end.
My Code
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
if collectionView == self.bannerClcView {
let cellSize = CGSize.init(width: view.frame.size.width, height: view.frame.size.height)
return cellSize
}else if collectionView == self.category {
let cellSize = CGSize.init(width: (self.category.frame.size.width/3), height: category.frame.size.width/3)
return cellSize
}else {
let cellSize = CGSize.init(width: (recomended_Ads_Clc.frame.size.width/2), height: 220)
return cellSize
}
}
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
}
How can I remove the spacing? Please help.

Answer 1

If you open your Storyboard where you've laid out your UICollectionView and select its trailing constraint, I image you'll see something like this in the Attributes inspector:
You'll need to uncheck "Relative to margin" to remove the extra space you're seeing.

Answer 2

Your mistake is with the source view that you compute the width property for the cell inside the function
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
instead of
let cellSize = CGSize.init(width: (recomended_Ads_Clc.frame.size.width/2), height: 220)
return cellSize
write return CGSize(width: (collectionView.frame.width / 2) - 10, height: 220)
And compute the height as you want. 10 will be the space between the cells