using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace ConsoleApplication1
{
  class Program
  {
    abstract public class Test
    {
      public virtual void Prinf()
      {
        Console.WriteLine("Abstract Printf...");
      }
 
    }
    public class Class1 : Test
    {
      public override void Prinf()
      {
         
        Console.WriteLine("Class One Override Printf...");
      }
    }
    public class Class2 : Test
    {
      public new void Prinf()
      {
         
        Console.WriteLine("Class Two New Printf...");
      }
    }
 
    static void Main(string[] args)
    {
      Class1 cls1 = new Class1();
      Class2 cls2 = new Class2();
      cls1.Prinf();
      cls2.Prinf();
      ((Test)cls1).Prinf();
      ((Test)cls2).Prinf();
      Console.ReadLine();
    }
  }
}

class Base 
{
 public virtual void F1() 
 {
  Console.WriteLine("Base's virtual function F1");
 }
 public virtual void F2() 
 {
  Console.WriteLine("Base's virtual fucntion F2");
 }
}
class Derived:Base 
{
 public override void F1() 
 {
  Console.WriteLine("Derived's override function F1");
 }
 public new void F2() 
 {
  Console.WriteLine("Derived's new function F2");
 }
}
class Program 
{
 public static void Main(string[] args) 
 {
  Base b1 = new Derived();
  //由于子类覆盖了父类的方法，因此这里调用的是子类的F1方法。也是OO中多态的体现 
  b1.F1();
  //由于在子类中用new隐藏了父类的方法，因此这里是调用了隐藏的父类方法 
  b1.F2();
 }
}