CollectionView Cell Auto resizing

Question

I have created a UICollectionView in which I have one prototype cell. I want 2 cells per row and running it on smaller screen gives me on one cell per row. The distance between cells gets increased on bigger screen. I am talking only with respect to iPhones.

I think I have to set constrains programmatically by taking screen width and divide it by 2. I know how to take screen width and divide it by 2 but I don't know how to give width and heights to cell programmatically.

Answer 1

UICollectionViewDelegateFlowLayout defines a method for this purpose.

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
     // return a CGSize 
 }

Example:

class MyViewController : UIViewController, UICollectionViewDelegateFlowLayout {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.collectionView.delegate = self
        self.collectionView.dataSource = self
    }

  // ...

    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
        return CGSize(width: CGFloat(self.view.frame.size.width / 2), height: self.view.frame.size.height) 
    }

  // ...
}