public class my_Events : UIElement
    {
        // Определяем событие
        public static readonly RoutedEvent AddMessageToQueueEvent;

        // Регистрируем событие
        static my_Events()
        {
            my_Events.AddMessageToQueueEvent = EventManager.RegisterRoutedEvent(
                "AddMessageToQueue", RoutingStrategy.Bubble,
                typeof(RoutedEventHandler), typeof(my_Events));
        }

        // Оболочка события
        public event RoutedEventHandler AddMessageToQueue
        {
            add
            {
                base.AddHandler(my_Events.AddMessageToQueueEvent, value);
            }
            remove
            {
                base.RemoveHandler(my_Events.AddMessageToQueueEvent, value);
            }
        } // AddMessageToQueue
    }

public partial class App : Application
{
        public static readonly RoutedEvent AddMessageToQueueEvent;

        static App()
        { 
               AddMessageToQueueEvent = my_Events.AddMessageToQueueEvent.AddOwner(typeof(App));
        }

.....

}