ios - swift:CollectionView 单元格大小

Question

我有 collectionView 对 superview 的约束。我想获得 iPhone X 的结果:

但是我明白了:

如何解决？

代码:

func numberOfSections(in collectionView: UICollectionView) -> Int {
        return 4
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 3
    }

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {


        cellOffset = 10

        cellWidth = (667 / 3)  - (cellOffset * 4)
        cellHeight =  (cellWidth / 2 * 3) + (cellWidth / 2 * 0.65)

        return CGSize(width: cellWidth, height: cellHeight)
    }

更新

更新

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

        let sectionInset = collectionView.frame.width / 3.0
        let margins = CGFloat(10.0 * 2.0)
        let width = (collectionView.frame.width - sectionInset - margins) / 3.0
        let height = collectionView.frame.height - 40.0

        let collectionViewLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout
        collectionViewLayout?.sectionInset = UIEdgeInsets(top: 0, left: 6.0, bottom: 0, right: 6.0)
        collectionViewLayout?.minimumInteritemSpacing = 10
        collectionViewLayout?.invalidateLayout()

        return CGSize(width: width, height: height)
    }

结果:

Answer 1

如果你想要横向的 3 个单元格

let cellWidth = ( self.collectionView.frame.width - 2 * cellOffset ) / 3