Firebase观察者值会影响所有集合视图单元格

Question

我在应用程序的主视图控制器上有一个带有UIButton的集合视图，当用户更改其状态时，都需要对其进行更改。

我使用的是Firebase观察者值，所以当值更改后，它将立即更改按钮的颜色和图像。

问题是，当我从第二个单元格向前更改值时，它将所有单元格都更改为。

为了更好的理解，我添加了图片：

This is the cells before changing the value of the second one.

And this is the what happens after I changed only the second cell values on firebase

如您所见，它也会影响第一个单元格。 该观察者的值使用事务块从另一个视图控制器更改。

我在Google上搜索了此问题，发现了类似的问题，但没有一个答案可以解决此问题。

这是集合视图的代码：

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "group_card_cell", for: indexPath) as! HomeGroupCollectionViewCell

    cell.prepareForReuse()
    cell.groupName.text = groups[indexPath.row].name
    cell.groupSchedule.text = "\(groups[indexPath.row].day!), Around \(groups[indexPath.row].time!)"

    cell.cardMoreButtonRef.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
    cell.cardMoreButtonRef.tag = indexPath.row

        //Changing card attending color and value:
        self.ref.child("Groups").child(groups[indexPath.row].uid!).child("groupFriendsList").child(currentUser!.uid).observe(.value) { (snapshot) in
            guard let value = snapshot.value as? String else {return}

            switch value{
            case "Going":
                cell.groupAttendButtonRef.backgroundColor = UIColor.init(named: "GoingColor")
                cell.groupAttendButtonRef.setImage(UIImage(named: "icons8-checkmark_filled"), for: .normal)
            case "Not Going":
                cell.groupAttendButtonRef.backgroundColor = UIColor.init(named: "NotGoingColor")
                cell.groupAttendButtonRef.setImage(UIImage(named: "icons8-delete_sign_filled"), for: .normal)
            case "Maybe":
                cell.groupAttendButtonRef.backgroundColor = UIColor.init(named: "MaybeColor")
                cell.groupAttendButtonRef.setImage(UIImage(named: "icons8-minus_math_filled"), for: .normal)
            default:
                cell.groupAttendButtonRef.backgroundColor = UIColor.init(named: "MaybeColor")
                cell.groupAttendButtonRef.setImage(UIImage(named: "icons8-minus_math_filled"), for: .normal)
            }
        }
    return cell
}

谢谢！

Answer 1

您是否尝试过在Firebase事件回调中为特定indexPath检索cell？
您可以使用-
let specificCell = collectionView.cellForItem(at: IndexPath(row: row, section: section))
以仅基于indexPath的单元格
或者您可以使用重用标识符获取它-

let idpath = IndexPath(row: indexPath.row-1, section: indexPath.section)
let specificCell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: idpath)

一旦有了该单元格，就可以相应地设置该单元格的groupAttendButtonRef。