CODEWITHSUNDEEP
swiftuicollectionviewuicollectionviewcell
andrey
andrey

Reputation: 1175

Wrong index in button inside collectionViewCell after deletion cell

I have a collectionView. Every cell contains button actionButton to remove them. Button have method removeItem to remove them thru attached target. I have an array datas contains items for collection.

override func collectionView(_ collectionView: UICollectionView, willDisplay cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {
        super.collectionView(collectionView, willDisplay: cell, forItemAt: indexPath)
        guard let cell = cell as? ViewCell else { return }
        let index = indexPath.row % datas.count
        let item = datas[index]
        cell.item = item
        cell.actionButton.tag = indexPath.item
        cell.actionButton.addTarget(self, action: #selector(removeItem), for: .touchUpInside)
    }

I have a method to delete item from collection view.

@objc func removeItem(sender: UIButton) {
    let indexPath = IndexPath.init(item: sender.tag, section: 0)
    self.datas.remove(at: indexPath.item)
    collectionView?.deleteItems(at: [indexPath])
}

But after deletion item from collection cells button index not reloaded. For example if I remove 1-st item with index [0, 0] next(second) item became 1-st but it's button index still [0, 1].

What i'm doing wrong and why button index don't rearranges?

Upvotes: 0

Views: 799

Answers (1)

rmaddy
rmaddy

Reputation: 318944

Never use tags to track the index path of a cell (in a collection view or a table view). As you've seen, it fails when you can insert, remove, or reorder cells.

The proper solution is to get the index path of the cell based on the location of the button in the collection view.

@objc func removeItem(sender: UIButton) {
    if let collectionView = collectionView {
        let point = sender.convert(.zero, to: collectionView)
        if let indexPath = collectionView.indexPathForItem(at: point) {
            self.datas.remove(at: indexPath.item)
            collectionView.deleteItems(at: [indexPath])
        }
    }
}

Upvotes: 2

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