如何在Swift中顯示帶有UICollectionView的UIViewController？

Question

帶有UICollectionView的UIViewController工作正常，如果我從故事板中啓動它。然而，當我嘗試推出這樣的：

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

它崩潰上線：

collectionView.dataSource = self 

的問題是，如何展現一個UIViewController（具有UICollectionView）模態正常嗎？

Answer 1

替換：

let imagePicker = imagePickerControllerViewController() 

有了：

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