3. 第一章：C#面向对象编程之继承和多态

 1     public abstract class Creature
 2     {
 3         private string _spiece;
 4 
 5         public Creature(string spiece)
 6         {
 7             this._spiece = spiece;
 8         }
 9 
10         public string Spiece
11         {
12             get { return this._spiece; }
13         }
14 
15         public abstract void Breath();
16     }

 1     public class Animal : Creature
 2     {
 3         private bool? _sex;
 4 
 5         public Animal(string spiece)
 6             : base(spiece)
 7         {
 8             this._sex = null;
 9         }
10 
11         public bool? Sex
12         {
13             get { return _sex; }
14         }
15 
16         public virtual void Run()
17         {
18             Console.WriteLine("I am running...");
19         }
20 
21         public override void Breath()
22         {
23             Console.WriteLine("I am breathing by animal respiration...");
24         }
25     }

 1     public class Monkey : Animal
 2     {
 3         public Monkey(string spiece)
 4             : base(spiece) { }
 5 
 6         public void ClimbTree()
 7         {
 8             Console.WriteLine("I am climbing tree...");
 9         }
10 
11         public override void Run()
12         {
13             Console.WriteLine("I am running with two legs, sometimes with four legs...");
14         }
15 
16         public override void Breath()
17         {
18             Console.WriteLine("I am breathing with lung...");
19         }
20     }

 1     public class Fish : Animal
 2     {
 3         public Fish(string spiece)
 4             : base(spiece) { }
 5 
 6         public override void Run()
 7         {
 8             Console.WriteLine("I am running in the water with fins...");
 9         }
10 
11         public override void Breath()
12         {
13             Console.WriteLine("I am breathing with cheek...");
14         }
15     }

 1     public class Plant : Creature
 2     {
 3         public Plant(string spiece)
 4             : base(spiece) { }
 5 
 6         public override void Breath()
 7         {
 8             Console.WriteLine("I am breathing by plant respiration...");
 9         }
10     }

 1     public class Tree : Plant
 2     {
 3         public Tree(string spiece)
 4             : base(spiece) { }
 5 
 6         //重载Breath()内部调用base.Breath()，其实和不写没啥区别，这里只是想告诉大家本质是什么。
 7         public override void Breath()
 8         {
 9             base.Breath();
10         }
11     }

 1     class Program
 2     {
 3         static void Main(string[] args)
 4         {
 5             Creature creature001 = new Animal("Animal");
 6             Console.WriteLine(creature001.Spiece);
 7             creature001.Breath();
 8 
 9             Console.WriteLine("—————————————————————————");
10 
11             Creature creature002 = new Plant("Plant");
12             Console.WriteLine(creature002.Spiece);
13             creature002.Breath();
14 
15             Console.WriteLine("—————————————————————————");
16 
17             Animal animal001 = new Animal("Animal", true);
18             Console.WriteLine(animal001.Spiece);
19             Console.WriteLine(string.Format("Spiece:{0}; Sex:{1}", animal001.Spiece, GetSexName(animal001.Sex)));
20             animal001.Breath();
21             animal001.Run();
22 
23             Console.WriteLine("—————————————————————————");
24 
25             Creature monkey001 = new Monkey("Monkey", true);
26             Console.WriteLine(monkey001.Spiece);
27             monkey001.Breath();
28 
29             Console.WriteLine("—————————————————————————");
30 
31             Animal animal002 = new Monkey("Monkey", false);
32             Console.WriteLine(animal002.Spiece);
33             Console.WriteLine(string.Format("Spiece:{0}; Sex:{1}", animal002.Spiece, GetSexName(animal002.Sex)));
34             animal002.Breath();
35             animal002.Run();
36 
37             Console.WriteLine("—————————————————————————");
38 
39             Creature fish001 = new Fish("Fish", true);
40             Console.WriteLine(fish001.Spiece);
41             monkey001.Breath();
42 
43             Console.WriteLine("—————————————————————————");
44 
45             Animal fish002 = new Fish("Fish", true);
46             Console.WriteLine(fish001.Spiece);
47             Console.WriteLine(string.Format("Spiece:{0}; Sex:{1}", fish002.Spiece, GetSexName(fish002.Sex)));
48             fish002.Breath();
49             fish002.Run();
50 
51             Console.WriteLine("—————————————————————————");
52 
53             Animal animal004 = new Monkey("Monkey", false);
54             Console.WriteLine(animal004.Spiece);
55             Console.WriteLine(string.Format("Spiece:{0}; Sex:{1}", animal004.Spiece, GetSexName(animal004.Sex)));
56             animal002.Breath();
57             animal002.Run();
58 
59             Console.WriteLine("—————————————————————————");
60 
61             Monkey jack = new Monkey("Monkey", true);
62             Console.WriteLine(jack.Spiece);
63             Console.WriteLine(string.Format("Spiece:{0}; Sex:{1}", jack.Spiece, GetSexName(jack.Sex)));
64             jack.Breath();
65             jack.Run();
66             jack.ClimbTree();
67 
68             Console.ReadLine();
69         }
70 
71         private static string GetSexName(bool? value)
72         {
73             string sexName = null;
74             if (value == null)
75             {
76                 sexName = "undefined";
77             }
78             else
79             {
80                 sexName = value.Value ? "male" : "female";
81             }
82             return sexName;
83         }
84     }