# `BCCollectionViewDelegate collectionView:willShowGroupHeader:forGroup:`

*Instance Method*

## Declaration

```swift
optional func collectionView(_ iconView: BCCollectionView!, willShowGroupHeader viewController: NSViewController!, forGroup group: Any!)
```

```objc
- (void) collectionView:(BCCollectionView *) iconView willShowGroupHeader:(NSViewController *) viewController forGroup:(id) group;
```

```python
collectionView_willShowGroupHeader_forGroup_(iconView: BCCollectionView, viewController: NSViewController, group: object)
```