UICollectionView Set number of columns

Question

I just started learning about UICollectionViews. I\'m wondering if anyone knows how to specify the number of columns in a collectionview. The default is set to 3 (iPhone/por

Answer 1

Expanding on noob's answer:

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

        let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
        let totalSpace = flowLayout.sectionInset.left
            + flowLayout.sectionInset.right
            + (flowLayout.minimumInteritemSpacing * CGFloat(numberOfItemsPerRow - 1))
        let size = Int((collectionView.bounds.width - totalSpace) / CGFloat(numberOfItemsPerRow))
        return CGSize(width: size, height: size)
}

This allows for any spacing between the cells. It assumes an Int member variable called numberOfItemsPerRow and also that all the cells are square and the same size. As noted in jhilgert00's answer we must also react to orientation changes, but now by using viewWillTransitionToSize as willRotateToInterfaceOrientation is depreciated.