i have written a collection class to handle undo/redo. Below are the steps i followed to write my own undo/redo.

[code snippet] of my collection class:
List<NodeSnap> _Snaps = new List<NodeSnap>();

public class NodeSnap
{
       public string DiagramString
       {  get;   set; }
}


1) When ever new node has been added/draged the existing node, then diagram string to be saved inside my collection object.

2) Press "Ctrtl + z", that time i'll take the recent  diagram string from the collectin & load it in the diagram.

Reason why i'm storing the entire diagram string is, i do not want to show much difference to the user when they do undo/redo. But my approch seems to be like performace degrade.

Is there any other custom approach to handle my scenario?

Yes, sometimes origin of the node is not retained properly.

Soon i'll send you the project. How to send my sample project?? Through e-mail or attaching with the post?