关于object类

class Point

    {

        public int x, y;

        public Point(int x, int y)

        {

            this.x = 

            this.y = y;

        }

        public override bool Equals(object obj)

        {

            // If this and obj do not refer to the same type, then they are not equal.

            if (obj.GetType() != this.GetType()) return false;

            // Return true if  x and y fields match.

            Point other = (Point)obj;

            return (this.x == other.x) && (this.y == other.y);

        }

        // Return the XOR of the x and y fields.

        public override int GetHashCode()

        {

            return x ^ y;

        }

        // Return the point's value as a string.

        public override String ToString()

        {

            return String.Format("({0}, {1})", x, y);

        }

        // Return a copy of this point object by making a simple field copy.

        public Point Copy()

        {

            return (Point)this.MemberwiseClone();

        }

    }

    public sealed class App

    {

        static void Main()

        {

            // Construct a Point object.

            Point p1 = new Point(1, 2);

            // Make another Point object that is a copy of the first.

            Point p2 = p1.Copy();

            // Make another variable that references the first Point object.

            Point p3 = p1;

            // The line below displays false because p1 and p2 refer to two different objects.

            Console.WriteLine(Object.ReferenceEquals(p1, p2));

            // The line below displays true because p1 and p2 refer to two different objects that have the same value.

            Console.WriteLine(Object.Equals(p1, p2));

            // The line below displays true because p1 and p3 refer to one object.

            Console.WriteLine(Object.ReferenceEquals(p1, p3));

            // The line below displays: p1's value is: (1, 2)

            Console.WriteLine("p1's value is: {0}", p1.ToString());

            Console.ReadLine();

        }

    }

 // This code produces the following output.

    //

    // False

    // True

    // True

    // p1's value is: (1, 2)