rx-swift - 使用 RxDataSource 自动调整 collectionViewCells 的大小

Question

如何使用RxDataSource实现自动调整collectionViewCells的大小？

我尝试过设置

flowLayout.estimatedItemSize = CGSize(width: 187, height: 102)

但是当 dataSourceObservable 更改时应用程序崩溃。

我尝试过在内部设置单元格大小

dataSource.configureCell = { [weak self] (dataSource, collectionView, indexPath, _) in 

这不是一个好主意，因为单元格重叠，这是因为我没有使用

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

现在，是否可以仅使用可观测值来正确布局单元格大小？这不是调用类似的东西

dataSourceVar.value[indexPath].cellSize

在collectionView sizeForItemAt里面？

Answer 1

遇到类似的问题，这样解决

// swiftlint:disable line_length type_name
final class RxCollectionViewSectionedReloadDataSourceAndDelegate<Section: SectionModelType>: RxCollectionViewSectionedReloadDataSource<Section>, UICollectionViewDelegateFlowLayout {
    typealias CellSize = (CollectionViewSectionedDataSource<Section>, UICollectionView, UICollectionViewLayout, IndexPath, Item) -> CGSize
    typealias SizeViewInSection = (CollectionViewSectionedDataSource<Section>, UICollectionView, UICollectionViewLayout, Int, Section) -> CGSize
    
    private var cellSize: CellSize
    private var headerSectionViewSize: SizeViewInSection?
    private var footerSectionViewSize: SizeViewInSection?
    
    init(
        configureCell: @escaping ConfigureCell,
        configureSupplementaryView: ConfigureSupplementaryView? = nil,
        moveItem: @escaping MoveItem = { _, _, _ in () },
        canMoveItemAtIndexPath: @escaping CanMoveItemAtIndexPath = { _, _ in false },
        cellSize: @escaping CellSize,
        headerSectionViewSize: SizeViewInSection? = nil,
        footerSectionViewSize: SizeViewInSection? = nil
    ) {
        self.cellSize = cellSize
        self.headerSectionViewSize = headerSectionViewSize
        self.footerSectionViewSize = footerSectionViewSize
        super.init(
            configureCell: configureCell,
            configureSupplementaryView: configureSupplementaryView,
            moveItem: moveItem,
            canMoveItemAtIndexPath: canMoveItemAtIndexPath
        )
    }
    
    override func collectionView(
        _ collectionView: UICollectionView,
        observedEvent: Event<RxCollectionViewSectionedReloadDataSource<Section>.Element>
    ) {
        collectionView.delegate = self
        super.collectionView(collectionView, observedEvent: observedEvent)
    }
    
    func collectionView(
        _ collectionView: UICollectionView,
        layout collectionViewLayout: UICollectionViewLayout,
        sizeForItemAt indexPath: IndexPath
    ) -> CGSize {
        cellSize(self, collectionView, collectionViewLayout, indexPath, self[indexPath])
    }
    
    func collectionView(
        _ collectionView: UICollectionView,
        layout collectionViewLayout: UICollectionViewLayout,
        referenceSizeForHeaderInSection section: Int
    ) -> CGSize {
        headerSectionViewSize?(self, collectionView, collectionViewLayout, section, sectionModels[section]) ?? .zero
    }
    
    func collectionView(
        _ collectionView: UICollectionView,
        layout collectionViewLayout: UICollectionViewLayout,
        referenceSizeForFooterInSection section: Int
    ) -> CGSize {
        footerSectionViewSize?(self, collectionView, collectionViewLayout, section, sectionModels[section]) ?? .zero
    }
}
// swiftlint:enable line_length type_name