void UpdateAppointment() { if (!ModelState.IsValid) { return; } ValidationSchedule[] schedules = SchedulerDataHelper.GetAppointmentsToUpdate <ValidationSchedule>( SchedulerDataHelper.CustomDataObject, SchedulerDemoHelper.CustomAppointmentStorage); foreach (var schedule in schedules) { if (!TryValidateModel(schedule)) { ViewData["EditableSchedule"] = schedule; break; } CarsDataProvider.UpdateSchedule <ValidationSchedule>(schedule); } }