# `BCCollectionViewDelegate collectionView:didSelectItemsAtIndexes:oldSelection:`

*Instance Method*

## Declaration

```swift
optional func collectionView(_ collectionView: BCCollectionView!, didSelectItemsAt newSelection: IndexSet!, oldSelection: IndexSet!)
```

```objc
- (void) collectionView:(BCCollectionView *) collectionView didSelectItemsAtIndexes:(NSIndexSet *) newSelection oldSelection:(NSIndexSet *) oldSelection;
```

```python
collectionView_didSelectItemsAtIndexes_oldSelection_(collectionView: BCCollectionView, newSelection: NSIndexSet, oldSelection: NSIndexSet)
```