IVsTextBuffer.GetUndoManager Method (IOleUndoManager)
Returns the undo manager for this buffer.
Assembly: Microsoft.VisualStudio.TextManager.Interop (in Microsoft.VisualStudio.TextManager.Interop.dll)
[out] Pointer to the IOleUndoManager interface.
This method might require considerable resources, depending upon the underlying implementation of the buffer. That is, it might be very difficult to calculate the size of the buffer if it is a virtual-line-oriented implementation as in Visual Basic.