The OfficeNavigationBar control can be integrated with a NavBarControl or an AccordionControl. When you assign a NavBarControl or AccordionControl to the NavigationClient property, the navigation control's groups are obtained and presented as items in the current OfficeNavigationBar. At runtime, when an end-user clicks any of these items, a corresponding group is automatically activated in the bound navigation control. For the NavBarControl, group activation is only noticeable when the NavBarControl is painted using the NavigationPaneView or SideBarView. For the AccordionControl, when its AccordionControl.ViewMode property is set to AccordionViewMode.NavigationPane.
In this integration mode, do not manually specify items via the Items or ItemsSource property.