using System.Windows.Controls; namespace HandyControl.Controls { public class PropertyItemsControl : ListBox { protected override bool IsItemItsOwnContainerOverride(object item) => item is PropertyItem; public PropertyItemsControl() { #if !NET40 VirtualizingPanel.SetIsVirtualizingWhenGrouping(this, true); VirtualizingPanel.SetScrollUnit(this, ScrollUnit.Pixel); #endif } } }