Occurs when an end-user clicks a navigation item in the navigation control.
The CustomShowNavigationItem event handler receives an argument of the CustomShowNavigationItemEventArgs type.
This event is raised as a result of calling the ShowNavigationItem method, which serves as the Navigation Action's SingleChoiceAction.Execute event handler. If you need to show a custom View or a separate form, handle this event. Use the handler's CustomShowNavigationItemEventArgs.ActionArguments.SelectedChoiceActionItem parameter, to get the clicked item. Set the handler's CustomShowNavigationItemEventArgs.Handled parameter to true to avoid display of the default View set for the clicked item. To see an example, refer to the How to: Implement Custom Context Navigation topic.
As an alternative to this event, you can override the ShowNavigationItem method in the ShowNavigationItemController's descendant. To see an example, refer to the How to: Create a New Object using the Navigation Control topic.