Transparent ViewController to See Parent Below?

Question

I would like to modally add a view controller with a transparent background, so the parent view controller beneath can be seen. (This is in an app for iPhone, not for iPad.)

Answer 1

For completeness and having it up-to-date, I am also adding the solution for Swift:

either

viewController.modalPresentationStyle = .CurrentContext 

being - A presentation style where the content is displayed over only the presenting view controller’s content.

or

viewController.modalPresentationStyle = .OverCurrentContext

being - A presentation style where the content is displayed over only the parent view controller’s content. The views beneath the presented content are not removed from the view hierarchy when the presentation finishes. So if the presented view controller does not fill the screen with opaque content, the underlying content shows through.

Depending on the requirements and circumstances for the presentation.