需求:选中答题卡中一个选项,下次进入答题卡,选中的题在屏幕中.
实现的页面
因为要实现选中的滚动居中效果,使用tableView在cell内部添加Button的方式很难实现(尝试无果后放弃),只能使用CollectionView来实现.具体实现代码:
1.自定义header和cell
collectionView.register(AnswerCardCollectionViewCell.self, forCellWithReuseIdentifier: "answerCardCellId")
collectionView.register(AnswerCardHeaderView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "header")
// DataSource
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "answerCardCellId", for: indexPath) as! AnswerCardCollectionViewCell
cell.configData(model: sourceArray[indexPath.section].userAnswers[indexPath.row], fromePage: type, index: String(indexPath.row + 1))
return cell
}
func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
if kind == UICollectionView.elementKindSectionHeader {
let header = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader, withReuseIdentifier: "header", for: indexPath) as! AnswerCardHeaderView
header.configHeaderData(model: sourceArray[indexPath.section])
return header
} else {
return UICollectionReusableView()
}
}
2.计算headView的高
// 实现UICollectionViewDelegateFlowLayout代理方法
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
var height: CGFloat = 0
if (sourceArray[section].titel ?? "").isEmpty {
return CGSize(width: SCREEN_WIDTH, height: height)
} else if (sourceArray[section].projectInro ?? "").isEmpty {
height = 56
return CGSize(width: SCREEN_WIDTH, height: height)
} else {
let proInroH = (sourceArray[section].projectInro ?? "").getHeight(font: UIFont.systemFont(ofSize: 14), width: SCREEN_WIDTH - 40, lineSpacing: 1.5)
height = 66 + proInroH
return CGSize(width: SCREEN_WIDTH, height: height)
}
}
3.滚动CollectionView
collectionView.scrollToItem(at:IndexPath(item: row, section: section), at: .centeredVertically, animated:false)
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