I'm looking in to creating a game through the NDK using a NativeApplication for Gingerbread. I also want to be able to use the new in-app billing API Google is providing to developers though. I know it's not a finalized API just yet but I haven't seen an example of interacting with it through the NDK.
Does anyone have an idea of how it could be possible to use the in-app billing through the NDK or should I look into launching another Activity that uses the Java API?
The in-app billing API is a Binder interface. When you make a purchase request, the Market application takes over and displays a (partially transparent) activity on top of yours, which renders the purchase dialog.
If you want to access this through the NDK, my advice would be to make a bridge to the sample code we provide using JNI. I don't believe you have access to the Binder from the NDK.