How to draw a monochrome image, then "dump" it to a vector with wxWidgets and C++?

I'm making a program that requires an interface to draw in a 20x20 monochrome grid, then "dump" that grid to a boolean vector.

Curr开发者_JS百科ently I'm programming it with C++ and wxWidgets, but haven't found a way to create a grid to draw on, much less to "dump" said grid to a vector. Is there a way to do it with wxWidgets, or should I use a different system (e.g. GTK)?

Have a look at the classes in the wxDC hierarchy.