How to access cells that will appear, before they appear?

Question

I have a collection view, but cell that are not appearing in the screen i cannot access, 1...5 ok, and those at index parth row 6, 7, and they have to be scrolled to bee seen

func Action0(sender: UIButton!) {
    for i in 0...7 {
        if i != 0{
        var indexPath = NSIndexPath(forRow: i, inSection: 0)
        var cell = collectionView!.cellForItemAtIndexPath(indexPath)
        cell!.backgroundColor = UIColor.whiteColor()
        }else{
        var indexPath = NSIndexPath(forRow: 0, inSection: 0)
        var cell = collectionView!.cellForItemAtIndexPath(indexPath)
        cell!.backgroundColor = UIColor.blueColor()
        }
    }
}

How to acces those cells that are not yet visible?

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CollectionViewCell", forIndexPath: indexPath) as! CollectionViewCell
    cell.backgroundColor = UIColor.blackColor()
    cell.textLabel.text = "\(indexPath.section):\(indexPath.row)"
    cell.buttonView.setBackgroundImage(UIImage(named: "Good"), forState: UIControlState.Normal)
    cell.buttonView.addTarget(self, action: Selector("Action\(indexPath.row):"), forControlEvents: UIControlEvents.TouchUpInside)
    return cell
}

score 3 · Accepted Answer · answered May 22 '15 at 23:57

3

Cells that are not yet visible do not exist. Table views and collection views only create just the cells that are currently visible. When you scroll, the cells that go out of view get recycled and reused for the new index path(s) that come into view.

You need to think in terms of your data model, which holds the data for each index path, and cells, which display a view of of subset of some of that data.

answered May 22 '15 at 23:57

Duncan C

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Is this function that I added to the post the one that does the creation and/or recycling? – Josip Bogdan May 23 '15 at 00:03
1

@JosipBogdan In your code, `collectionView.dequeueReusableCellWithReuseIdentifier(_:forIndexPath:)` creates or recycles an existing view. – Brian Nickel May 23 '15 at 00:06
I tried few things and still not working, can i get a little more push? – Josip Bogdan May 23 '15 at 00:36

How to access cells that will appear, before they appear?

1 Answers1