Hello Karl,
When the EditAppointmentDialog displays the resources in its ItemsControl it expects that the passed item is of type
ResourceTypeViewModel but in the scenario when accessing the resources from outside the control the item in the ItemsControl is of type
ResourceType. All that is needed is to create a custom ResourceTypeTemplateSelector that inherits DataTemplateSelector and override its SelectTemplate method. Next you will need to make sure the bindings are correct.
We created a sample project that represents the described approach with one ItemsControl and a ScheduleView with two resources. Give it a try.
Regards,
Vladi
the Telerik team