cell.isSelected 不能作为方面工作

Question

我的 collectionView 单元格上有一个 longtapgesture。如果我在一个单元格上点击 0.3 秒，该单元格会出现绿色边框，并且 cell.isSelected 更改为 true。 问题是，当我滚动 collectionView 时，边框消失并且我选择的所有单元格都是错误的。

    func setupLongTapGesture() {
        let longPressGesture:UILongPressGestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(longPress))
        longPressGesture.minimumPressDuration = 0.3
        longPressGesture.delegate = self
        collectionView.addGestureRecognizer(longPressGesture)
    }
    
    @objc func longPress(_ longPressGestureRecognizer: UILongPressGestureRecognizer) {
        
        if longPressGestureRecognizer.state == UIGestureRecognizer.State.began {
            
            let touchPoint = longPressGestureRecognizer.location(in: self.collectionView)
            if let indexPath = collectionView.indexPathForItem(at: touchPoint) {
                let cell = collectionView.cellForItem(at: indexPath) as! DetailCollectionViewCell
                
                if cell.isSelected == true {
                    cell.layer.borderColor = UIColor.clear.cgColor
                    cell.layer.borderWidth = 2
                    cell.layer.cornerRadius = 20
                    cell.isSelected = false
                } else if cell.isSelected == false {
                    cell.layer.borderColor = UIColor.green.cgColor
                    cell.layer.borderWidth = 2
                    cell.layer.cornerRadius = 20
                    cell.isSelected = true
                }
                
            }
        }
    }

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        let width = collectionView.frame.width / 2
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "DetailCollectionViewCell", for: indexPath) as! DetailCollectionViewCell
        
        cell.cellWidth = width
        cell.roundedView.frame = CGRect(x: 0, y: 0, width: width - 5 , height: width - 5)
        
        cell.layer.masksToBounds = false
        cell.layer.shadowColor = UIColor.black.cgColor
        cell.layer.shadowOpacity = 0.1
        cell.layer.shadowRadius = 2
        cell.layer.shadowOffset = CGSize.zero
        
        print(indexPath.row, cell.isSelected)
        
        if cell.isSelected != true {
            cell.layer.borderColor = UIColor.clear.cgColor
        } else {
            cell.layer.borderColor = UIColor.green.cgColor
        }
        
        return cell
    }

Answer 1

单元格被重复使用，您需要将该数据（cell.isSelected 选择状态）保留在模型中

if cell.isSelected != true {
   cell.layer.borderColor = UIColor.clear.cgColor
} else {
   cell.layer.borderColor = UIColor.green.cgColor
}