class Test
        {
            public static int temp;
            public int mNum;
            public int mNum2 = 2;
            public void Look()
            {
                Console.WriteLine("看我，我是test");
                Console.WriteLine("mNum={0}", mNum);
            }
            private int mNum3 = 3;
            private readonly int mNum4 = 4;
            public int Num3
            {
                get { return mNum3; }
                set { mNum3 = value; }
            }
            public Test()
            {
                temp = 1;
                mNum = 0;
            }
        }

 class A : Test
        {
            readonly int x = 1;
            public A()
            {
                PrintFields();
                Look();
            }

            readonly int c;
            readonly int sd = 6;
            public virtual void PrintFields()
            {
                Console.WriteLine("j={0},k={1}", "AA", "AA");
            }
        }
        class B : A
        {
            readonly int y;
            int z = 2;
            public B()
            {
                z = -1;
            }
            public override void PrintFields()
            {
                Console.WriteLine("x={0},y={1}", "b", z);
            }
        }
        class C : B {
            int x = 1;
            int y = 3;
            public override void PrintFields() {
                Console.WriteLine("j={0},k={1}", "CC", y);
            }
        }


        static void Main(string[] args)
        {
            Console.WriteLine("======实例化Test======");
            Test test = new Test();
            Console.WriteLine("======实例化A======");
            A a = new A();
            Console.WriteLine("======实例化B======");
            B b = new B();
            Console.WriteLine("======实例化C======");
            C c = new C();
            Console.ReadKey();
        }