Thank you for contacting us.
The idea you have about populating RadPanelBar's children collection is really very cool. To dynamically add and remove items you will have to call the Clear method of the panelbar's items collection and then probably you have to add the new items when you have parsed the XML file. It would be great if you send us the sample after you finish it.
If you have any other questions please write me back.
the Telerik team
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