C#  Copy Code
public bool UndoEnabled { get; set; }

Visual Basic  Copy Code
Public Property UndoEnabled As Boolean

 Property Value

You might need to disable undo:

• before executing actions you don't want end-users to undo, for example creating special start/end nodes.
• before creating programmatically a lot of new diagram items - say hundreds or thousands. MvcDiagram creates an undo record for each item creation; if the Capacity of the command history is smaller than the number of items created, most of the records will drop from the history queue while adding new ones. That would waste processing power and memory for creating undo records that won't be used.

UndoManager Members
UndoManager Class
MindFusion.Diagramming Namespace