Question

I would like to provide an undo/redo facility in my application.

As an example, consider this series of invocations:

gr.Drawrectangle(pen, p1, p2);
gr.FillEllipse(brush, p1, dx, dy);

I’d like to store the invocations in a list of some kind and be able to undo them. What is a good way to do this?

Answer 1

I do not understand completely that what you want but can create a list of actions or functions.

List<Action<Graphics>> actions = new List<Action<Graphics>>();

actions.Add(gr => gr.Drawrectangle(pen, p1, p2));
actions.Add(gr => gr.FillEllipse(brush, p, x, y));