UICollectionViewLayout - 2 列中的 3 个单元格

Question

我正在尝试创建一个具有 7 单元重复布局的 UICollectionView，如下所示：

但是，使用 CollectionViewLayout，我似乎无法将第 6 和第 7 个单元格放入同一列。

以下是相关代码：

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let collectionViewWidth = self.collectionView.bounds.width
        let flowLayout = collectionViewLayout as! UICollectionViewFlowLayout
        let spaceBetweenCells = flowLayout.minimumInteritemSpacing
        var adjustedWidth = collectionViewWidth - spaceBetweenCells

        if indexPath.row % 7 == 0 {
            return CGSize(width: collectionViewWidth, height: collectionViewWidth)
        }

        if indexPath.row % 7 == 1 || indexPath.row % 7 == 2 || indexPath.row % 7 == 3 {
            adjustedWidth = collectionViewWidth - (spaceBetweenCells * 2)
            return CGSize(width: floor(adjustedWidth / 3), height: floor(adjustedWidth / 3))
        }

        if indexPath.row % 7 == 4 {
            adjustedWidth = collectionViewWidth - spaceBetweenCells * 2
            return CGSize(width: floor(adjustedWidth / 3) * 2 + spaceBetweenCells, height: floor(adjustedWidth / 3) * 2 + spaceBetweenCells)
        }

        if indexPath.row % 7 == 5 || indexPath.row % 7 == 6 {
            adjustedWidth = collectionViewWidth - spaceBetweenCells * 2
            return CGSize(width: floor(adjustedWidth / 3), height: floor(adjustedWidth / 3))
        }

        let width: CGFloat = adjustedWidth / 2
        let height: CGFloat = width;
        return CGSize(width: width, height: height)
    }

结果如下：

我什至尝试为最后两个单元格使用较小的高度，以确保高度不是问题。感谢您的帮助。

---

更新 我通过 UIStackViews 让它工作了，虽然很烦人。

Answer 1

仅使用UICollectionViewFlowLayout 的sizeForItem 方法并不是一件容易的事。你必须使用

if indexPath.row % 7 == 0 || indexPath.row % 7 == 4 {
    return CGSize(width: collectionViewWidth, height: collectionViewWidth)
}

然后在cellForItemAt方法内：

if indexPath.row % 7 == 4 {
    // Provide a UIStackView with your required layout
    // Or maybe even you could provide a smaller UICollectionView with just 3 cells, but that seems like overkill.
}