# `BCCollectionViewDelegate collectionViewLostFirstResponder:`

*Instance Method*

## Declaration

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

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

```python
collectionViewLostFirstResponder_(collectionView: BCCollectionView)
```