Ios 拖放；删除UICollectionView单元重用问题

因此，我为UICollectionView实现了如下拖放：

func collectionView(_ collectionView: UICollectionView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
        guard shouldAllowDragForIndexPath?(indexPath) == true else { return [] }
        guard let cell = collectionView.cellForItem(at: indexPath)?.toImage() else {
            return []
        }
        let provider = NSItemProvider(object: cell)
        let item = UIDragItem(itemProvider: provider)
        item.localObject = data[indexPath.row]

        return [item]
    }

    func collectionView(_ collectionView: UICollectionView, performDropWith coordinator: UICollectionViewDropCoordinator) {
        guard
            let item = coordinator.items.first?.dragItem,
            let sourceIndexPath = coordinator.items.first?.sourceIndexPath,
            let destinationIndexPath = coordinator.destinationIndexPath,
            let entity = item.localObject as? T
            else {
                return
        }
        collectionView.performBatchUpdates({ [unowned self] in
            dropEntityAtIndexPath?(entity, destinationIndexPath)
            self.collectionView.deleteItems(at: [sourceIndexPath])
            self.collectionView.insertItems(at: [destinationIndexPath])
        }, completion: nil)
        coordinator.drop(item, toItemAt: destinationIndexPath)
        item.localObject = nil
    }

    func collectionView(_ collectionView: UICollectionView, dropSessionDidUpdate session: UIDropSession, withDestinationIndexPath destinationIndexPath: IndexPath?) -> UICollectionViewDropProposal {
        if
            session.localDragSession != nil,
            let path = destinationIndexPath,
            shouldAllowDropForIndexPath?(path) == true {
            return UICollectionViewDropProposal(operation: .move, intent: .insertAtDestinationIndexPath)
        } else {
            return UICollectionViewDropProposal(operation: .forbidden)
        }
    }

一切正常，但我发现当细胞被重复使用时有奇怪的行为。 以下是视频：

所以它只发生在单元格被拖动之后，而且看起来有一些灰色的叠加视图，但我在视图调试器上看不到它。此外，我还尝试在

prepareforeuse

中设置单元格的

imageView.image=nil

，但没有效果。如果有人帮我解决这个问题，我将非常感激。谢谢

Edit1:在cellForItemAt中编码：

override func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(for: indexPath, cellType: PhotoCollectionViewCell.self)
        let container = data[indexPath.row].postContainer,
        let post = container.postMedia.first
        let isCarousel = container.isCarousel
        let isVideo = post.isVideo
        let _isSelected = isSelected?(indexPath) ?? false
        let url = post.thumbURL?.toURL()
        let isScheduled = container.schedulerFor != nil
        let fromInstagram = false

        cell.configure(url: url, isSelected: _isSelected, isVideo: isVideo, isCarousel: isCarousel, isScheduled: isScheduled, fromInstagram: fromInstagram)

    return cell
}

编辑2 单元配置功能：

func configure(url: URL?, isSelected: Bool = false, isVideo: Bool = false, isCarousel: Bool = false, isScheduled: Bool = false, fromInstagram: Bool = false) {
        checkmarkImageView.isHidden = !isSelected
        selectionOverlay.isHidden = !isSelected
        isVideoImageView.isHidden = !isVideo
        carouselImageView.isHidden = !isCarousel
        cornerImageView.image = isScheduled ? R.image.cyanCorner() : R.image.grayCorner()
        instagramImageView.isHidden = !fromInstagram
        cornerImageView.isHidden = fromInstagram
        url.map(imageView.setImage(with:))
    }

---

我认为问题不是单元重用，而是模型更新不当<代码>项。本地数据应在移动完成后正确更新

这意味着您必须在调用

UICollectionView

update之前更新数据模型对象

以下是

UICollectionViewDelegate

的示例，但实际上只有这几行很重要：

// YOUR MODEL OBJECT is expected to be a list-like data structure
YOUR_MODEL_OBJECT.insert(YOUR_MODEL_OBJECT.remove(at: sourceIndex), at: destinationIndex)

它如何适用于

UICollectionViewDelegate

func collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) {
    guard destinationIndexPath != sourceIndexPath else { return }
    // YOUR MODEL OBJECT is expected to be a list-like data structure
    YOUR_MODEL_OBJECT.insert(YOUR_MODEL_OBJECT.remove(at: sourceIndex), at: destinationIndex)
}

---

您的

cellForItem（at:）

函数是什么样子的？@JacobRelkin添加到问题中……您的

配置
函数是什么样子的？@JacobRelkin添加到问题中。@JacobRelkin如果以前发生过拖放，则总是在滚动之后。谢谢您的回答，我已经尝试了您的解决方案，但它对我没有帮助：(