Swift 3.0、Xcode 8 の回答
1.コレクションビューデリゲートを設定していることを確認してください
class DashboardViewController: UIViewController {
@IBOutlet weak var dashboardCollectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
dashboardCollectionView.delegate = self
}
}
2. UICollectionViewDelegate ではなく、 UICollectionViewDelegateFlowLayoutプロトコルを実装します。
extension DashboardViewController: UICollectionViewDelegateFlowLayout {
fileprivate var sectionInsets: UIEdgeInsets {
return .zero
}
fileprivate var itemsPerRow: CGFloat {
return 2
}
fileprivate var interitemSpace: CGFloat {
return 5.0
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let sectionPadding = sectionInsets.left * (itemsPerRow + 1)
let interitemPadding = max(0.0, itemsPerRow - 1) * interitemSpace
let availableWidth = collectionView.bounds.width - sectionPadding - interitemPadding
let widthPerItem = availableWidth / itemsPerRow
return CGSize(width: widthPerItem, height: widthPerItem)
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAt section: Int) -> UIEdgeInsets {
return sectionInsets
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0.0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return interitemSpace
}
}