An example of registering your interface.
// Register ExceptionMessageServiceImpl ServiceRegistry.GetInstance().RegisterService(typeof(Sybase.Mobile.Framework.IExceptionMessageService), ExceptionMessageServiceImpl.GetInstance()); try { // throw Sybase.Persistence.ObjectNotFoundException } catch (ObjectNotFoundException e) { if (e.ErrorCode == ObjectNotFoundException.VALUE_IS_NULL) { string msg = e.Message; msg = e.GetLocalizedMessage("fr"); msg = e.GetLocalizedMessage("es"); msg = e.GetLocalizedMessage("de"); } } // Register CustomExceptionMessageService ServiceRegistry.GetInstance().RegisterService(typeof(Sybase.Mobile.Framework.IExceptionMessageService), new CustomExceptionMessageService()); try { // throw Sybase.Persistence.ObjectNotFoundException } catch (ObjectNotFoundException e) { if (e.ErrorCode == ObjectNotFoundException.VALUE_IS_NULL) { string msg = e.Message; msg = e.GetLocalizedMessage("fr"); msg = e.GetLocalizedMessage("es"); msg = e.GetLocalizedMessage("de"); } } finally { // Unregister CustomExceptionMessageService ServiceRegistry.GetInstance().UnregisterService<Sybase.Mobile.Framework.IExceptionMessageService>(typeof(Sybase.Mobile.Framework.IExceptionMessageService)); }