The bounds of the Item is determined by the ItemSize property. Note that while you can indirectly affect the size of the items by using ScalingEffectStops, scaling effects are applied to items at render time after the setting of this property has taken effect.
When the AutoScalItemContentsToFit property is set to false, scrollbars will be shown by default within the item if necessary (i.e., if the size of the contents is greater than the size of the item) to enable scrolling of the contents. For explicit control over whether scrollbars are displayed in this case, you can set the ItemHorizontalScrollBarVisibility and ItemVerticalScrollBarVisibility properties.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, 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