The RadPanelBar control is used for displaying a list of items in a Silverlight application and is often used for building collapsible side-menu interfaces. The RadPanelBar control has the following features:

• Data binding that allows the control to be populated from various data sources
• Programmatic access to the RadPanelBar object model which allows developers to dynamically create PanelBars, populate them with items, and set their properties.
• Customizable appearance through built-in or user-defined skins.
• Enhanced accessibility by support for keyboard navigation.

Items

The RadPanelBar control is made up of a tree-like structure of items represented by RadPanelBarItem objects. Items at the first level (level 0) are called root items. An item that has a parent item is called a child item. All root items are stored in the Items collection. Child items are stored in a parent item's Items collection.

Each item has a Header and an Item property. The value of the Header property is always visible in the RadPanelBar control whenever a RadPanelBarItem is collapsed or expanded, while the Item property is used to store the actual content of the RadPanelBarItem i.e. what is visible when the RadPanelBarItem is expanded.