static void Main(string[] args)
{
IFactory factory = new UndergraduteFactory();
LeiFeng student = factory.createLeiFeng();
student.BuyRice();
student.Sweep();
student.Wash();
Console.Read();
}
static void Main(string[] args)
{
IFactory factory;
LeiFeng student;
factory = new UndergraduteFactory();
student = factory.CreateLeiFeng();
student.BuyRice();
student.Sweep();
student.Wash();
factory = new VolunteerFactory();
student = factory.CreateLeiFeng();
student.BuyRice();
student.Sweep();
student.Wash();
Console.ReadLine();
}