Returns the selected item within the Accordion control.
A BootstrapClientAccordionItem object that represents the selected item.
If the ASPxNavBar.AllowSelectItem property is set to true, end users are allowed to select items via mouse clicks. The selected item can be obtained on the client side by using the GetSelectedItem method,
If none of the items is selected within an Accordion control or selecting is prohibited, the GetSelectedItem method returns null.
In order to select a specific item on the client side, use the Accordion's BootstrapClientAccordion.SetSelectedItem method.