ios - UITableViewCell 内的 UICollectionView 始终返回空，即使显示为选定状态

Question

我在 UITableViewCell 中使用 UICollectionView。我可以选择 UICollectionView 内的单元格。但是当我尝试获取 UICollectionView 或选定的单元格时，结果始终为 null。我已经在这个问题上停留了很长时间。我在下面添加了我的代码供您引用。

class WeekDaysSelCell: UITableViewCell,UICollectionViewDelegate, UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {

    var weekdays = ["S", "M", "T", "W", "T", "F", "S"]

    var weekdaysSelected = [String]()

    @IBOutlet var weeklyDaysColView: UICollectionView!

    override func awakeFromNib() {
        super.awakeFromNib()
        self.weeklyDaysColView.delegate = self
        self.weeklyDaysColView.dataSource = self
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 7
    }

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

        let cell : WeekDaysCollCell = weeklyDaysColView.dequeueReusableCell(withReuseIdentifier: "weekday", for: indexPath) as! WeekDaysCollCell

        cell.weekDayLabel.text = weekdays[indexPath.row]
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

        let cell : WeekDaysCollCell = self.weeklyDaysColView.cellForItem(at: indexPath) as! WeekDaysCollCell
        if (cell.backgroundColor == UIColor.gray) {
            cell.backgroundColor  = UIColor.clear
            weekdaysSelected.removeAll { $0 == String(indexPath.row)}
            //print("Removed from weekdaysSelected:", indexPath.row)
        } else {

            cell.backgroundColor = UIColor.gray
            cell.isSelected = true
            //weeklyDaysColView.selectItem(at: indexPath, animated: true, scrollPosition: [])
            weekdaysSelected.append(String(indexPath.row))
            //print("Added to weekdaysSelected:", indexPath.row)
        }
    }
}

// Trying to get the collection view from inside a willMove(toParent parent: UIViewController?) method. 

    override func willMove(toParent parent: UIViewController?) {
            super.willMove(toParent: parent)
            if parent == nil
            {

                if let delegate = self.delegate {
                print("Inside If condition")

                // Code that i use to get the cell 
                let cell3 = tableView.dequeueReusableCell(withIdentifier: "cell3") as! WeekDaysSelCell

                    print(cell3.weekdaysSelected)

                    print(cell3.weeklyDaysColView.indexPathsForSelectedItems)

                    // Trying to pass selected cells
                    //delegate.repeatCustomSelection(selectedIdx: String(lastSelection.row),repeatCustomSel: repeatCustomSelection)
                }
            }
        }

Answer 1

您正在尝试在 willMove(toParent Parent: UIViewController?) 中获取可重用的单元格，这不会返回您预期的单元格。

您需要使用索引路径获取单元格。

func cellForRow(at indexPath: IndexPath) -> UITableViewCell?