如何在Swift中顯示帶有UICollectionView的彈出式UIViewController？

Question

如果我從情節提要中啟動，帶有UICollectionView的UIViewController可以正常工作。 但是，當我嘗試像這樣啟動它時：

let imagePicker = imagePickerControllerViewController()
imagePicker.modalPresentationStyle = .OverCurrentContext
presentViewController(imagePicker, animated: true, completion: nil)

它崩潰在線：

collectionView.dataSource = self

問題是，如何正確顯示模態顯示的UIViewController（具有UICollectionView）？

Answer 1

替換為：

let imagePicker = imagePickerControllerViewController()

附：

let imagePicker = storyboard.instantiateViewControllerWithIdentifier("imagePicker") as! imagePickerControllerViewController