public RoastSchedule(Guid id, DateTime roastWeekStartsOn)
{
RoastDays = new RoastDays(new HashSet <RoastDay>());
//不仅把event放到集合中，还调用本类的Apply方法
ApplyChange(new RoastScheduleCreatedEvent(id, roastWeekStartsOn));
}
public void SetRoastDays(RoastDays roastDays)
{
if (roastDays.Days.Count == 0)
{
throw new ArgumentNullException("roastDays count must be greater than 0");
}
var newDays = roastDays.Days.Select(t => t.Day).ToArray();
ApplyChange(new RoastScheduleRoastDayChosenEvent(Id, newDays));
}
//
public void Apply(RoastScheduleRoastDayChosenEvent e)
{
RoastDays = new RoastDays(e.Days);
}