Hi Ross,

Using the event handler in MVVM application is not recommended. You can easily capture the selected tab in your VM through the SelectedIndex property of the UXTabControl. For instance, "SelectedIndex={Binding MyVM.SelectedTabIndex}"

In your case, the EventTrigger is treated as a content and thus a tab is created to encapsulate the content, which is no longer needed when you used the correct MVVM design pattern. The "content encapsulation" complies with the ItemsControl concept in which it allows you to host any UIElement in the control.

Please let me know if my suggestion works for you, or if you have specific reasons to use EventTrigger.

Hope this helps,
Jimmy