我需要显示UICollectionView中每个单元格的分隔符，除了一个部分的每个第一个单元格。我使用列表布局。到目前为止，我只能使用configuration.showsSeparators = false删除所有分隔符。
我的UICollectionView配置：

let collectionView: UICollectionView = {
    let provider = { (_: Int, layoutEnv: NSCollectionLayoutEnvironment) -> NSCollectionLayoutSection? in
        var configuration = UICollectionLayoutListConfiguration(appearance: .grouped)
        configuration.showsSeparators = true // <----- shows separators for every cell
        configuration.footerMode = .supplementary
        return .list(using: configuration, layoutEnvironment: layoutEnv)
    }
    let listLayout = UICollectionViewCompositionalLayout(sectionProvider: provider)
    return UICollectionView(frame: .zero, collectionViewLayout: listLayout)
}()

小区注册：

let cellRegistration = UICollectionView.CellRegistration<MailboxCell, MailAccount> {
    (cell, indexPath, listItem) in
    // some setup code
}

dataSource = UICollectionViewDiffableDataSource<Account, ListItem>(collectionView: collectionView) { 
    (collectionView, indexPath, listItem) -> UICollectionViewCell? in

    // some setup
    return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: listItem)
}