CornerExtent is expressed as a percent of the length of each side, or as a percent of the sweep angle before each corner. The corner will begin at this percentage length. Sensible values are between 50 and 100.
This property wil have a different effects under different circumstances in rendering the dial. For rectangular dials, the CornerExtent simply applies to the four corners of the rectangle. For elliptical dials, no corners will be rendered if the dial sweeps 360 degrees or more.
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