Enum ?

        [Flags]

        public enum DinnerItems

        {

            None = 0,

            Entree = 1,

            Appetizer = 2,

            Side = 4,

            Dessert = 8,

            Beverage = 16,

            BarBeverage = 32

        }



        private void button3_Click(object sender, EventArgs e)

        {

            //Enum.HasFlag 确定当前实例中是否设置了一个或多个位域。 



            DinnerItems myOrderA = DinnerItems.Appetizer | DinnerItems.Entree | DinnerItems.Beverage | DinnerItems.Dessert;

            DinnerItems myOrderB = DinnerItems.Appetizer | DinnerItems.Entree;



            bool a = (myOrderA & myOrderB) == myOrderB;

            bool b = myOrderA.HasFlag(myOrderB);



            Console.WriteLine(a); //Output:True

            Console.WriteLine(b); //Output:True



        }

Windows8 C#2013 Code 
问题：从某种程度上说 
(myOrderA & myOrderB) == myOrderB 是不是等效于 myOrderA.HasFlag(myOrderB); ？
------解决方案--------------------
myOrderA & myOrderB != 0，包含myOrderB
------解决方案--------------------
注意，前提是有[Flags]这个attribute
------解决方案--------------------

是地。两者等同
------解决方案--------------------
ht