Performs an undo or redo action.
Assembly: System.Design (in System.Design.dll)
Undo actions toggle themselves between undo and redo states, so calling twice sets the object back to its original state.
The UndoEngine.UndoUnit class initially assumes that the undoable work has already been done, so the first call to undoes the work. The next call undoes the previous undo operation, performing a redo.
The method calls the UndoCore method to perform an undo operation. The method itself works to maintain consistent state within the UndoEngine.UndoUnit, even in the event of an exception thrown by UndoCore.Notes to Inheritors:
Do not call the UndoCore method directly; override it if you want, but always call the public method to perform undo work. The method notifies the undo engine to suspend undo data gathering until the current undo operation is completed. This prevents new undo units from being created in response to this unit doing work.
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.