Exception处理机制

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace ConsoleApplication2
 7 {
 8     class Program
 9     {
10         static void Main(string[] args)
11         {
12             //Level1
13             try
14             {               
15                 //Level2
16                 try
17                 {
18                     
19                     //Level3
20                     try
21                     {
22                         //throw new ExceptionA("Exception in Level3");
23                         //throw new ExceptionB("Exception in Level3");
24                     }
25                     catch (ExceptionA)
26                     {
27                         Console.WriteLine("Level3中处理Exception");
28                     }
29                     finally
30                     {
31                         Console.WriteLine("Level3中的finally语句块");
32                     }
33                     throw new ExceptionC("Exception in Level2");
34                 }
35                 catch (ExceptionB)
36                 {
37                     Console.WriteLine("Level2中处理Exception");
38                 }
39                 finally
40                 {
41                     Console.WriteLine("Level2中的finally语句块");
42                 }
43                 //throw new Exception("Exception in Level1");
44             }
45             catch (ExceptionC)
46             {
47                 Console.WriteLine("Level1中处理ExceptionC");
48             }
49             catch (Exception)
50             {
51                 Console.WriteLine("Level1中处理Exception");
52             }
53             finally
54             {
55                 Console.WriteLine("Level1中的finally语句块");
56             }
57 
58 
59             Console.ReadKey();
60 
61         }
62     }
63 }

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace ConsoleApplication2
 7 {
 8     class ExceptionA : Exception
 9     {
10         public ExceptionA(string mess):base(mess)
11         {
12         }
13     }
14 }

首先在同级查找是否存在兼容的异常，如果没有，则一级一级往上