How to get Gdk::Pixbuf from Gnome::Canvas::CanvasAA ??

[Ramon Liu <ramon liu 1220 gmail com>]

Hi There! ^^

I'm a beginner for Gnome. I'm use Gnome::Canvas::CanvasAA class to
implement my graphic program, like libgnomecanvasmm-2.26.0/demo/primitives.cc code. it can be work now, no matter draw line, circle, box, pic... etc.

and now, I would like to save graphic window into bmp format, just think about use Glib::RefPtr<Gdk::Pixbuf>, but I don't known how to get it!

does have any idea? @@?
or maybe somebody can provider some links to me,
thanks ! ^^"

Ramon.