ios - CollectionViewCell 不持久

Question

我不完全确定如何问这个问题，但这是我认为很重要的代码......一切都已连接并正常工作(我在单元格上遗漏了其他设计代码以使问题更具可读性)

在第一个代码片段中，我有我的自定义单元格，它将相关变量“inCurrentMonth”默认为 False

class DateCollectionViewCell: UICollectionViewCell {


public var inCurrentMonth: Bool!

required init?(coder aDecoder: NSCoder) {
    super.init(coder:aDecoder)
    //You Code here
    inCurrentMonth = false
}

在下面的代码片段中，我正在为每个单元格打印变量 inCurrentMonth - 这总是打印错误

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Calendar", for: indexPath) as! DateCollectionViewCell
    print(cell.inCurrentMonth)
}

最后一段代码显示 Collection View 在出队时更新每个单元格的“inCurrentMonth”变量。如果我在归还单元格之前打印单元格，它们显然具有正确的 incurrentmonth 值。不管怎样，这个信息什么时候会恢复到错误值？

编辑:在出队时更新时，标签上文本的值在 Collection View 中正确显示

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Calendar", for: indexPath) as! DateCollectionViewCell

    switch Direction {  

    case 0:
        if indexPath.row < DaysInMonths[month] + NumberOfEmptyBox{
            cell.DateLabel.text = "\(indexPath.row + 1 - NumberOfEmptyBox)"
            cell.inCurrentMonth = true
        } else {
            cell.DateLabel.text = "\(indexPath.row - DaysInMonths[month] - NumberOfEmptyBox + 1)"
            cell.DateLabel.textColor = UIColor.lightGray
            cell.inCurrentMonth = false
        }
    case 1:
        if indexPath.row < DaysInMonths[month] + NextNumberOfEmptyBox{
            cell.DateLabel.text = "\(indexPath.row + 1 - NextNumberOfEmptyBox)"
            ?????????????THIS DOES WORK?????????????
            cell.inCurrentMonth = true
        } else {
            !!!!!!!!!!!!!THIS DOES NOT WORK!!!!!!!!!!!!!!!
            cell.DateLabel.text = "\(indexPath.row - DaysInMonths[month] - NextNumberOfEmptyBox + 1)"
            cell.DateLabel.textColor = UIColor.lightGray
            cell.inCurrentMonth = false
        }
    case -1:
        if indexPath.row < DaysInMonths[month] + PreviousNumberOfEmptyBox{
            ?????????????THIS DOES WORK?????????????
            cell.DateLabel.text = "\(indexPath.row + 1 - PreviousNumberOfEmptyBox)"
            !!!!!!!!!!!!!THIS DOES NOT WORK!!!!!!!!!!!!!!!
            cell.inCurrentMonth = true
        } else {
            cell.DateLabel.text = "\(indexPath.row - DaysInMonths[month] - PreviousNumberOfEmptyBox + 1)"
            cell.DateLabel.textColor = UIColor.lightGray
            cell.inCurrentMonth = false
        }
    default:
        fatalError()
    }

    if Int(cell.DateLabel.text!)! < 1 { //here we hide the negative numbers or zero

        var previousMonth: Int = month-1
        if previousMonth == -1 {
            previousMonth = 11
        }
        let previousDay: Int = DaysInMonths[previousMonth] - NumberOfEmptyBox + (indexPath.row) + 1
        cell.DateLabel.text = "\(previousDay)"
        cell.DateLabel.textColor = UIColor.lightGray
        cell.inCurrentMonth = false
    }

Answer 1

in the code snippet below I am printing the variable inCurrentMonth for each of the cells - THIS ALWAYS PRINTS FALSE

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Calendar", for: indexPath) as! DateCollectionViewCell
    print(cell.inCurrentMonth)
}

dequeueReusableCell 创建单元格的新实例，而不是使用 func cellForItem(at: IndexPath) -> UICollectionViewCell? UICollectionView 方法>