# `BCCollectionViewDelegate collectionViewSelectionDidChange:`

*Instance Method*

## Declaration

```swift
optional func collectionViewSelectionDidChange(_ collectionView: BCCollectionView!)
```

```objc
- (void) collectionViewSelectionDidChange:(BCCollectionView *) collectionView;
```

```python
collectionViewSelectionDidChange_(collectionView: BCCollectionView)
```