VirtualizingPanel.IsVirtualizing Attached Property
Gets or sets a value that indicates that this VirtualizingPanel is virtualizing its child collection.
Assembly: PresentationFramework (in PresentationFramework.dll)
The standard layout system creates item containers and computes layout for each item associated with a list control. The word "virtualize" refers to a technique by which a subset of UI elements are generated from a larger number of data items based on which items are visible on-screen. Generating many UI elements when only a few elements might be on the screen can adversely affect the performance of your application. For example, the VirtualizingStackPanel calculates the number of visible items and works with the ItemContainerGenerator from an ItemsControl (such as ListBox or ListView) to create UI elements only for visible items.
The following example shows how to bind to an XML data source and virtualize the items displayed in a ListBox element by using XAML. Notice that the P:System.Windows.Controls.VirtualizingStackPanel.IsVirtualizing attached property is explicitly set to true.