1、IOException

1 public static void Test1() 2         { 3             FileStream fs = null; 4             try 5             { 6                 fs = new FileStream("d:\\file.txt", FileMode.Open); 7                 fs.ReadByte(); 8                 Console.WriteLine("OK"); 9             }10             catch (IOException)11             {12                 Console.WriteLine("IOException");13             }14             catch15             {16                 Console.WriteLine("ELSE Exception");17             }18             finally19             {20                 if (fs != null)21                 {22                     fs.Close();23                     fs = null;24                 }25             }26         }

  2、FileNotFoundException 继承自 IOException

1         public static void Test1() 2         { 3             FileStream fs = null; 4             try 5             { 6                 fs = new FileStream("d:\\file.txt", FileMode.Open); 7                 fs.ReadByte(); 8                 Console.WriteLine("OK"); 9             }10             catch (FileNotFoundException)11             {12                 Console.WriteLine("FileNotFoundException");13             }14             catch (IOException)15             {16                 Console.WriteLine("IOException");17             }18             finally19             {20                 if (fs != null)21                 {22                     fs.Close();23                     fs = null;24                 }25             }26         }

 

  3、NullReferenceException

1         /// 
 2         /// 委托 3         /// 
 4         /// 委托参数 5         public delegate void Show(string str); 6  7         /// 
 8         /// 事件 9         /// 
10         public static event Show ShowEvent;11 12         public static void Test2()13         {14             try15             {16                 Console.WriteLine(ShowEvent.GetInvocationList().Count());17             }18             catch (NullReferenceException)19             {20                 Console.WriteLine("NullReferenceException");21             }22         }