Question

for my tile editor I have 2 stacks of TileMaps, undo and redo. Every time the user makes a change the state of the map is added to the stack, than the change is made. Here is my undo code:

private void undoToolStripMenuItem_Click(object sender, EventArgs e)
    {
        if (undo.Count != 0)
        {
            redo.Push(tileMap);
            tileMap = undo.Peek();
            undo.Pop();
        }
    }

The map however does not change. Why?

Answer 1

If it’s not a UI update issue…

Are your redo and undo references to different stack objects? If they both reference the same stack object, then your code would just push-and-pop the current state.

Or similarly, are you pushing another reference to the same tileMap object, or a copy of it? (i.e. You probably want to Push(tileMap.DeepCopy()))

Also, why do you Peek and then Pop? You can just Pop directly into tileMap.