It's quite complex: You need to add a series of controls for deciding what you want to paint and then implement the Paint event from a container such as a Picturebox, and then in the paint event use the drawing primitives in GDI+ to create all the graphics
selected by your drawing tool.
Since this is the Training and Certification forum, I would suggest taking a course that teaches the basics of drawing graphics. Course 2565 contained an explanation on GDI+ in module 6, but unfortunately it is an old course and at this moment I don't
recall whether any newer MOC explains GDI+.
Alternatively, you could read a book on the topic. I wrote a book that explains GDI+ in some detail (link),
but it is not written for beginners; the book presumes that you are already proficient at writing the rest of the application and explains only how to draw over it.
