how to make dynamic width of the UICollectionViewCell

Question

I want to set the width of UICollectionViewCell dynamically. I found some code in swift and I want the code in Objective-C.

let flowLayout = col         


        

Answer 1

Swift 2.2

override func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    var flowLayout = (collectionView.collectionViewLayout as! UICollectionViewFlowLayout)
    if indexPath.item % 3 == 0 {
        var cellWidth: Float = (CGRectGetWidth(collectionView.frame) - (flowLayout.sectionInset.left + flowLayout.sectionInset.right))
        return CGSizeMake(cellWidth, cellWidth / 2)
    }
    else {
        var cellWidth: Float = (CGRectGetWidth(collectionView.frame) - (flowLayout.sectionInset.left + flowLayout.sectionInset.right) - flowLayout.minimumInteritemSpacing) / 2
        return CGSizeMake(cellWidth, cellWidth)
    }
}

Swift 3.0

override func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    var flowLayout: UICollectionViewFlowLayout? = (collectionView.collectionViewLayout as? UICollectionViewFlowLayout)
    if indexPath.item % 3 == 0 {
        var cellWidth: Float? = (collectionView.frame.width - (flowLayout?.sectionInset?.left + flowLayout?.sectionInset?.right))
        return CGSize(width: CGFloat(cellWidth), height: CGFloat(cellWidth / 2))
    }
    else {
        var cellWidth: Float? = (collectionView.frame.width - (flowLayout?.sectionInset?.left + flowLayout?.sectionInset?.right) - flowLayout?.minimumInteritemSpacing) / 2
        return CGSize(width: CGFloat(cellWidth), height: CGFloat(cellWidth))
    }
}