.net初学之索引器

1.语法
(可有可无)[访问修饰符] 数据类型 this[数据类型标识符]
{
get{}
set{}
}
e.g:
 1 class Program
 2     {
 3         static void Main(string[] args)
 4         {
 5             Indexer ind = new Indexer(5);
 6             ind[0] = new animal("猫科", " 豹子");
 7             ind[1] = new animal("猫科", " 豹子1");
 8             ind[2] = new animal("猫科", " 豹子2");
 9             ind[3] = new animal("猫科", " 豹子3");
10             ind[4] = new animal("猫科", " 豹子4");
11  
12             for (int i = 0; i < 5; i++)
13             {
14                 Console.WriteLine(ind[i].show());
15             }
16         }
17     }
18  
19     public class animal
20     {
21         private string kemu;
22         public string Kemu
23         {
24             get { return kemu; }
25             set { kemu = value; }
26         }
27         private string name;
28         public string Name
29         {
30             get { return name; }
31             set { name = value; }
32         }
33         public animal() { }
34         public animal(string _kemu, string _name)
35         {
36             this.Kemu = _kemu;
37             this.Name = _name;
38         }
39         public string show()
40         {
41             return "名字" + Name + "科目是" + Kemu;
42         }
43     }
44     public class Indexer
45     {
46         public animal[] ani;
47         public Indexer(int count)
48         {
49             if (count < 0)
50                 Console.WriteLine("长度不合法");
51             ani = new animal[count];
52         }
53  
54         public animal this[int index]
55         {
56             get
57             {
58                 if (index > ani.Length)
59                     return null;
60                 return ani[index];
61             }
62             set { ani[index] = value; }
63         }
64     }