Multiple UICollectionViewCell color gets changed together issue - ios

Question

I have created a UICollectionView with 12 cells in it. I would like to have their color changed (to the same color) on tap.
Here is my code :
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
let cell = collectionView.cellForItemAtIndexPath(indexPath)as! InterestCollectionViewCell
print("2 \(cell.interest) \(indexPath.row)")
if cell.selected == true {
cell.backgroundColor = UIColor.redColor()
}
else {
cell.backgroundColor = UIColor.clearColor()
}
}
Issues
Color doesn't change back when tapped again
When I tap on the [0] cell, the [5] and [10] cells changes color as well. Same after I tap on the [1] cell, [6]and [11] cells get called too...etc.m

Answer 1

Instead of setting color in didSelectItemAtIndexPath set the color in cellForItemAtIndexPath for that you need to declare instance of Int and store the row of collectionView inside that instance like this.
var selectedRow: Int = -1
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath:NSIndexPath)->UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CELL", forIndexPath: indexPath) as! InterestCollectionViewCell
// Set others detail of cell
if self.selectedRow == indexPath.item {
cell.backgroundColor = UIColor.redColor()
}
else {
cell.backgroundColor = UIColor.clearColor()
}
return cell
}
Now in didSelectItemAtIndexPath set the selectedRow reload the collectionView.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
if self.selectedRow == indexPath.item {
self.selectedRow = -1
}
else {
self.selectedRow = indexPath.item
}
self.collectionView.reloadData()
}
Edit: For multiple cell selection create one array of indexPath and store the object of indexPath like this.
var selectedIndexPaths = [NSIndexPath]()
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath:NSIndexPath)->UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CELL", forIndexPath: indexPath) as! InterestCollectionViewCell
// Set others detail of cell
if self.selectedIndexPaths.contains(indexPath) {
cell.backgroundColor = UIColor.redColor()
}
else {
cell.backgroundColor = UIColor.clearColor()
}
return cell
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
if self.selectedIndexPaths.contains(indexPath) {
let index = self.selectedIndexPaths.indexOf(indexPath)
self.selectedIndexPaths.removeAtIndex(index)
}
else {
self.selectedIndexPaths.append(indexPath)
}
self.collectionView.reloadData()
}