C#之继承源代码

using System; using System.IO; public class CRunMain { public static void Main() { A a = new A(100); B b = new B(12); a.Print(); b.Print(); } } public class A { public const int MAXVAL = int.MaxValue; //常量，必须赋值 public readonly int AA = 0; //只读字段 public int x = 0; //实例字段 public int y = 0; public static int n = 0; public A(int a) { Random rand = new Random(); AA = a; x = rand.Next(); y = rand.Next(); n++; Console.WriteLine("construct of A has been called!"); } public void Print() { Console.WriteLine("x = {0}\t y = {0}", x, y); Console.WriteLine("total count of A: {0}", n); } } public class B:A { public int x = 0; public int y = 0; public B(int a):base(a) { Random rand = new Random(); x = rand.Next(); y = rand.Next(); Console.WriteLine("construct of A has been called!"); } public void Print() { Console.WriteLine("x = {0}\t y = {0}", x, y); } }