private void manageSchedule()
        {
            var tempSchedules = _dialogs.ShowSchedulesDialog(_manageScheduleEnabled, _schedules);

            if (tempSchedules != null)//此处可以这样写,是因为我们并没有直接修改BasicSchedule对象的成员
            {
                _schedules = tempSchedules;
                _enabledSchedules.Clear();
                _schedules.ForEach(bs => addEnabledSchedule(bs));
                updateDescription();
            }
        }