[部署iOS 13合成布局时遇到一个奇怪的问题。
我想隐藏集合视图标题并实现referenceSizeForHeaderInSection
方法,但是referenceSizeForHeaderInSection
无法在合成布局上使用
这是我的作品布局:
lazy var collectionViewLayout: UICollectionViewLayout = {
// item layout deploy
let cellItemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .fractionalHeight(0.2))
let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(0.33), heightDimension: .fractionalHeight(1.0))
let cellItem = NSCollectionLayoutItem(layoutSize: cellItemSize)
let item = NSCollectionLayoutItem(layoutSize: itemSize)
cellItem.contentInsets = NSDirectionalEdgeInsets(top: 4, leading: 4, bottom: 4, trailing: 4)
item.contentInsets = NSDirectionalEdgeInsets(top: 4, leading: 4, bottom: 4, trailing: 4)
// group layout deploy
let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .fractionalHeight(0.2))
let group = NSCollectionLayoutGroup.horizontal(layoutSize: groupSize, subitem: item, count: 3)
let containerGroupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .absolute(215))
let containerGroup = NSCollectionLayoutGroup.vertical(layoutSize: containerGroupSize, subitems: [cellItem, group, group, group, group])
// section layout deploy
let section = NSCollectionLayoutSection(group: containerGroup)
section.contentInsets = NSDirectionalEdgeInsets(top: 4, leading: 0, bottom: 4, trailing: 0)
// Headers layout deploy
let headerSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .absolute(18))
let header = NSCollectionLayoutBoundarySupplementaryItem(layoutSize: headerSize, elementKind: SupplementaryViewOfKind.Header.rawValue, alignment: .top)
section.boundarySupplementaryItems = [header]
let layout = UICollectionViewCompositionalLayout(section: section)
return layout
}()
实施viewForSupplementaryElementOfKind
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
guard
kind == SupplementaryViewOfKind.Header.rawValue,
let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: XXXHeader.identifier, for: indexPath) as? XXXHeader
else { return UICollectionReusableView() }
if isFullScreen {
// customer header with titleLabel property
header.titleLabel.text = segmentedControl.titleForSegment(at: indexPath.section)
} else {
header.titleLabel.text = nil
}
}
然后我尝试了referenceSizeForHeaderInSection
但无法工作
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
if isFullScreen {
return CGSize(width: collectionView.frame.width, height: 18)
} else {
return CGSize.zero
}
}
有什么想法或新方法可以隐藏“合成版面”页眉。
func configureDiffableDataSource() {
let dataSource = UICollectionViewDiffableDataSource<TripSection, TripItem>(collectionView: collectionView) {
(collectionView: UICollectionView, indexPath: IndexPath, item: TripItem) -> UICollectionViewCell? in
let cell = collectionView.dequeueCell(ofType: SmallTableViewCell.self, for: indexPath)
cell.fillWithData(tip)
return cell
}
}
// ADD elementKindSectionHeader如果为isFullScreen,则返回nil
dataSource.supplementaryViewProvider = { [weak self] (collectionView: UICollectionView, kind: String, indexPath: IndexPath) -> UICollectionReusableView? iln
guard let itamSequence = self?.dataSource?.itemIdentifier(for: indexPath) else { return nil }
guard let section = self?.dataSource?.snapshot().sectionIdentifier(containingItem: itamSequence) else { return nil }
let boardHeader = collectionView.dequeueReusableView(ofType: BoardSupplementaryView.self, forKind: UICollectionView.elementKindSectionHeader, for: indexPath)
return boardHeader
}
}
self.dataSource = dataSource
updateSnapshot(animated: false)
}