Thanks for your example last night. I look forward to examining it closer once you have made it available. I am struggling with assigning DataTemplates to the tab item in a customized TabControl. I have created and new dependency property TabItemDataTemplateName which I assign as the selected tab changes. See below. The source of the DataTemplate is a resource library. This does change the ContentTemplate as expected but does not change the appearance as I expect it to. Am I assigning the wrong TabItem Property? Actually, the first time through, the grid in the tabItem is rendered as expected. It is only when I change the TabItemDataTemplateName and assign it that nothing happens. I'd appreciate your thoughts.

if (TabItemDataTemplateName != null && TabItemDataTemplateName != "")
newitem.ContentTemplate = Application.Current.Resources[TabItemDataTemplateName] as DataTemplate;