Help How to set a delegate to Object C

e.g.
UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];

imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePickerController.delegate = ctrol;
imagePickerController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

[ctrol presentModalViewController:imagePickerController animated:YES];
[imagePickerController release];
———————————————————————-
imagePickerController.delegate = ctrol;

How to set this delegate to a imagePickerController in HelloWorldScene.mm(HelloWorldScene.cpp).