The index of the thumb (control point) being moved.
Remarks
The zero-based index of the thumb (control point) being moved. A thumb is being moved when the Operation is set to AnnEditDesignerOperation.MoveThumb. For other operations, the MoveThumbIndex is set to -1.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2