Cells inside UICollectionView do not render properly - ios

Question

I'm new to iOS and Swift, I'm trying to create a UICollectionView for the first time.
Something is not quite right when running what I made. Here's what it looks like in my storyboard:
But when I run:
Top grey area became longer than before and bottoms of the cells seem clipped. I just wrote few lines of code to make the cells' height equal to the collection view's.
let height = collectionView.frame.height
cell.frame.size.height = height
return cell
Any suggestions?

Answer 1

Swift 4 code is here
1) Uncheck the Automatic field of the Row Height in the attribute inspector.
2) Then set the delegate funcitons
extension ViewController : UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
var width = CGFloat(80) //change "80" with your cell width
return CGSize(width: width ,height : self.collectionView.frame.height)
}
}

Answer 2

Please use collectionViewLayout to give a size for an item,
class YourController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout
and
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let height = collectionView.frame.height
let width = UIScreen.main.bounds.width / 3
let size = CGSize(width: width, height: height)
return size
}

Answer 3

You can make changes from storyboard or from code. I have done from storyboard as shown in image.
And also write this method in your view controller to give a size to your item. For that inherit UICollectionViewDelegateFlowLayout method in your view controller.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let size = collectionView.frame.width / 3
return CGSize(width: size - 20, height: size - 20 )
}
Note: This is just an example. You can set your collection view cell frame.

Answer 4

To change height in a collection view, do not change the cell frame height. There is another delegate for the collection view to set cell height and width.
extension ViewControll : UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
{
return CGSize(width: anyWidth, height: collectionView.frame.size.height)
}
}
Here, anyWidth means whatever width you put. It's up to you