在我的项目中，我有一个UITableView，每当用户点击任何单元格时，该单元格的高度都会随着单元格内显示一些长文本而增加，当再次点击或点击另一个单元格时，单元格的高度会降低并显示一些短文本。(带有一些动画(
这是我的自定义手机代码：
class SomeCustomCell: UITableViewCell {
static let identifier = "SomeCustomCellId"
var shortDescLabel: AvatarLabel!
var longDescLabel: AvatarLabel!
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
backgroundColor = selected ? UIColor.lightGray.withAlphaComponent(0.5) : .clear
if selected {
didSelected()
} else {
deSelected()
}
}
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
selectionStyle = .none
shortDescLabel = AvatarLabel()
shortDescLabel.translatesAutoresizingMaskIntoConstraints = false
addSubview(shortDescLabel)
NSLayoutConstraint.activate([
shortDescLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 10),
shortDescLabel.topAnchor.constraint(equalTo: topAnchor, constant: 20),
shortDescLabel.heightAnchor.constraint(equalToConstant: 50),
shortDescLabel.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -10)
])
longDescLabel = AvatarLabel()
longDescLabel.alpha = 0.0
longDescLabel.numberOfLines = 0
longdateLabel.isHidden = true
longDescLabel.translatesAutoresizingMaskIntoConstraints = false
addSubview(longDescLabel)
NSLayoutConstraint.activate([
longDescLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 10),
longDescLabel.topAnchor.constraint(equalTo: topAnchor, constant: 20),
longDescLabel.heightAnchor.constraint(equalToConstant: 100),
longDescLabel.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -10)
])
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func didSelected() {
longDescLabel.isHidden = false
shortDescLabel.isHidden = true
UIView.animate(withDuration: 0.5) { [weak self] in
self?.shortDescLabel.alpha = 0.0
self?.longDescLabel.alpha = 1.0
}
}
func deSelected() {
longDescLabel.isHidden = true
shortDescLabel.isHidden = false
backgroundColor = .clear
UIView.animate(withDuration: 0.5) { [weak self] in
self?.shortDescLabel.alpha = 1.0
self?.longDescLabel.alpha = 0.0
}
}
func setSomeCustomCell(_ someModel: SomeModel) {
shortDescLabel.text = someModel.shortText
longDescLabel.text = someModel.longText
}
}
这是我的UITableView代码：
extension someViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if someModels.count == 0 {
tableView.setEmptyView()
} else {
tableView.restore()
}
return someModels.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: SomeCustomCell.identifier) as? SomeCustomCell else {
return SomeCustomCell()
}
let item = someModels[indexPath.row]
cell. setSomeCustomCell(item)
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if selectedCellIndexPath == indexPath {
self.selectedCellIndexPath = nil
guard let cell = tableView.cellForRow(at: indexPath) as? SomeCustomCell else { return }
cell.deSelected()
} else {
self.selectedCellIndexPath = indexPath
}
tableView.beginUpdates()
tableView.endUpdates()
if selectedCellIndexPath != nil {
// This ensures, that the cell is fully visible once expanded
tableView.scrollToRow(at: indexPath, at: .none, animated: true)
}
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if selectedCellIndexPath == indexPath {
return 140
}
return 90
}
}
但有一个问题，当用户点击某个单元格并再次点击它(单元格先变大，然后变小(，向下滚动(所选单元格现在不再显示在屏幕上(，然后向上滚动查看该单元格时，该单元格的高度很小，但显示的是长数据(而不是短数据(。为什么会发生这种情况，以及如何解决这个问题？
调用自己的func来更改"选择/未选择"；单元格的出现不会NOT通知表视图更改。
使用当前代码，当您第二次点击单元格时，您会告诉该单元格更改其外观，但据表视图所知，该单元格仍处于选中状态。
因此，当你向下滚动然后向上滚动时，表视图是"；重新选择"；自动显示行。
将您的didSelectRowAt更改为：
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if selectedCellIndexPath == indexPath {
self.selectedCellIndexPath = nil
// tell the table view to deselect the row!
tableView.deselectRow(at: indexPath, animated: true)
//guard let cell = tableView.cellForRow(at: indexPath) as? SomeCustomCell else { return }
//cell.deSelected()
} else {
self.selectedCellIndexPath = indexPath
}
tableView.beginUpdates()
tableView.endUpdates()
if selectedCellIndexPath != nil {
// This ensures, that the cell is fully visible once expanded
tableView.scrollToRow(at: indexPath, at: .none, animated: true)
}
}