The wall orientation will be flipped.
Namespace: Autodesk.Revit.DBAssembly: RevitAPI (in RevitAPI.dll) Version: 26.0.4.0 (26.0.4.0)
Syntaxmember Flip : unit -> unit
Remarks
For curtain walls and stacked walls, flip won't change the wall orientation. [!:Autodesk::Revit::DB::Wall.Orientation].
See Also