1 namespace Test
 2 {
 3     class Program
 4     {
 5         static void Main(string[] args)
 6         {
 7             //作业:橡皮rubber鸭子、木wood鸭子、真实的鸭子realduck。
 8             //三个鸭子都会游泳，而橡皮鸭子和真实的鸭子都会叫，
 9             //只是叫声不一样，橡皮鸭子“唧唧”叫，真实地鸭子“嘎嘎”叫，木鸭子不会叫.
10 
11             Duck dk = new RealDuck();
12             dk.Swim();
13             IBark ib = new RealDuck();
14             ib.Bark();
15             Console.ReadKey();
16         }
17     }
18     //为抽象类
19     public abstract class Duck
20     {
21         public abstract void Swim();
22     }
23     //接口
24     public interface IBark
25     {
26         void Bark();
27     }
28 
29     public class RealDuck : Duck, IBark
30     {
31         public void Bark()
32         {
33             Console.WriteLine("真的鸭子嘎嘎叫");
34         }
35 
36         public override void Swim()
37         {
38             Console.WriteLine("真的鸭子会游泳");
39         }
40     }
41 
42     public class MuDuck : Duck
43     {
44         public override void Swim()
45         {
46             Console.WriteLine("木头鸭子也会游泳");
47         }
48     }
49 
50     public class XPDuck : Duck, IBark
51     {
52         public void Bark()
53         {
54             Console.WriteLine("橡皮鸭子唧唧叫");
55         }
56 
57         public override void Swim()
58         {
59             Console.WriteLine("橡皮鸭子也会游泳");
60         }
61     }
62 }