ScrollTrackExtent is the width of the scroll track used to navigate between the tab items. The scroll track is only displayed when the Thumb enum is included in the ScrollButtonTypes property. The ScrollButtons property is used to determine when the scroll buttons should be displayed. By default, they are only displayed when there isn't enough room to display all the tab items.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, 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