当我开始水平滚动时，为啥我的收藏视图中的单元格被取消选择？
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【中文标题】当我开始水平滚动时，为啥我的收藏视图中的单元格被取消选择？【英文标题】：Why my cell in my collection view getting deselected when i start scrolling horizontally?当我开始水平滚动时，为什么我的收藏视图中的单元格被取消选择？ 【发布时间】：2020-05-22 11:55:30 【问题描述】：我想从集合视图中制作一个简单的日历。 [在此处输入图片描述][1][1]：https://i.stack.imgur.com/1yXhL.jpg 但是当我选择一个单元格并开始滚动时，单元格会自动取消选择。这是我的集合视图代码。
`let todayColor = UIColor(red: 242/255, green: 56/255, blue: 15/255, alpha: 1)
let otherDayColor = UIColor(red: 90/255, green: 90/255, blue: 90/255, alpha: 1)
var now = Date()
var day = DateFormatter()
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellID", for: indexPath) as! CalenderCell
cell.layer.cornerRadius = 5
cell.backgroundColor = otherDayColor
if indexPath.row == 0
cell.backgroundColor = todayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: Date()) - 1])
cell.dateLabel.text = now.string(format: "dd")
else if indexPath.row == 1
cell.backgroundColor = otherDayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 1)) - 1])
cell.dateLabel.text = myCalender(numDay: 1).string(format: "dd")
else if indexPath.row == 2
cell.backgroundColor = otherDayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 2)) - 1])
cell.dateLabel.text = myCalender(numDay: 2).string(format: "dd")
else if indexPath.row == 3
cell.backgroundColor = otherDayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 3)) - 1])
cell.dateLabel.text = myCalender(numDay: 3).string(format: "dd")
else if indexPath.row == 4
cell.backgroundColor = otherDayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 4)) - 1])
cell.dateLabel.text = myCalender(numDay: 4).string(format: "dd")
else if indexPath.row == 5
cell.backgroundColor = otherDayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 5)) - 1])
cell.dateLabel.text = myCalender(numDay: 5).string(format: "dd")
else if indexPath.row == 6
cell.backgroundColor = otherDayColor
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 6)) - 1])
cell.dateLabel.text = myCalender(numDay: 6).string(format: "dd")
return cell
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
if let cell = collectionView.cellForItem(at: indexPath)
if indexPath.row == 0
cell.backgroundColor = todayColor
else
cell.backgroundColor = UIColor.systemGreen
func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath)
if let cell = collectionView.cellForItem(at: indexPath)
cell.backgroundColor = otherDayColor
`
【问题讨论】：
单元格在退出屏幕然后进入时取消选择？ 【参考方案1】：这是因为您在 didSelect 方法中配置了选择颜色，但在 cellForItemAt 中没有配置。您需要使用所选项目索引创建变量（并将其设置为didSelect）并在cellForItemAt 中更新颜色管理。
在视图控制器中实现选定项索引：
var selectedItem: Int?
在您的集合视图委托方法中：
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellID", for: indexPath) as! CalenderCell
cell.layer.cornerRadius = 5
cell.backgroundColor = otherDayColor
if indexPath.row == 0
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: Date()) - 1])
cell.dateLabel.text = now.string(format: "dd")
else if indexPath.row == 1
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 1)) - 1])
cell.dateLabel.text = myCalender(numDay: 1).string(format: "dd")
else if indexPath.row == 2
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 2)) - 1])
cell.dateLabel.text = myCalender(numDay: 2).string(format: "dd")
else if indexPath.row == 3
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 3)) - 1])
cell.dateLabel.text = myCalender(numDay: 3).string(format: "dd")
else if indexPath.row == 4
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 4)) - 1])
cell.dateLabel.text = myCalender(numDay: 4).string(format: "dd")
else if indexPath.row == 5
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 5)) - 1])
cell.dateLabel.text = myCalender(numDay: 5).string(format: "dd")
else if indexPath.row == 6
cell.dayLabel.text = (day.shortWeekdaySymbols[Calendar.current.component(.weekday, from: myCalender(numDay: 6)) - 1])
cell.dateLabel.text = myCalender(numDay: 6).string(format: "dd")
if indexPath.row == 0
cell.backgroundColor = todayColor
else
if let selectedItem = selectedItem,
selectedItem == indexPath.row
// this cell is selected
cell.backgroundColor = UIColor.systemGreen
else
cell.backgroundColor = otherDayColor
return cell
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath)
if let cell = collectionView.cellForItem(at: indexPath)
selectedItem = indexPath.row // set selectedItem
if indexPath.row == 0
cell.backgroundColor = todayColor
else
cell.backgroundColor = UIColor.systemGreen
在didDeselectItemAt中需要设置selectedItem为nil。
使用switch-case 代替if 也很好
【讨论】：
没有。问题是一样的。当我滚动所有其他单元格时，只有最后一个单元格被取消选中。 你在 'didSelectItemAt' 中设置了 selectedItem = indexPath.row 吗？ 是的，我已将它添加到我的 didSelectItemAtIndex 函数中。 在底部的“cellForItemAt”中添加调试：cell.dateLabel.textColor = cell.backgroundColor以上是关于当我开始水平滚动时，为啥我的收藏视图中的单元格被取消选择？的主要内容，如果未能解决你的问题，请参考以下文章
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