1 class Program
2 {
3 // 值类型的反向转换，就是一个unbox，
4 static void Main(string[] args)
5 {
6 int totalCount;
7 ArrayList list = new ArrayList();
8
9 Console.WriteLine("Enter a number between 2 and 1000:");
10 totalCount = int.Parse(Console.ReadLine());
11
12 list.Add((double)0);// box，从 0 封装成double，再转换成一个object对象
13 list.Add((double)1);// box，从 0 封装成double，再转换成一个object对象
14
15 for (int count = 2; count < totalCount; count++)
16 {
17 list.Add((double)list[count - 1] + (double)list[count - 2]);// 2 unbox+1 box，把Object类型的数转换成double类型的数，再进行相加，最后在转换成object类型
18 }
19
20 foreach (double count in list)// unbox，从Object类型转换成double类型。
21 {
22 Console.Write("{0,5}",count);// box，从double类型转换成Object类型。
23 }
24 Console.WriteLine();
25 Console.WriteLine("----------------------------------------------------");
26
27 int number;
28 object thing;
29 double bigNumber;
30
31 number = 42;
32 thing = number;
33
34 try
35 {
36 bigNumber = (double)(int)thing;
37 Console.WriteLine(bigNumber);
38
39 }
40 catch (InvalidCastException exception)
41 {
42 Console.WriteLine("异常信息：{0},The Log is {1}",exception.Message,exception.Source);
43 }
44 }
45 }
