or
<telerik:RadListBox ItemsSource="{Binding TestItems}"> <telerik:RadListBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding }" FontWeight="Normal" FontSize="18" /> </DataTemplate> </telerik:RadListBox.ItemTemplate></telerik:RadListBox>If I use your RadTabControl, I get error 26 in the Output window. Why?
System.Windows.Data Error: 26 : ItemTemplate and ItemTemplateSelector are ignored for items already of the ItemsControl's container type; Type='RadTabItem'