Exception Handling in C# using try catch

Question

I have 3 Methods, I am try catch for every method. If an error occur in Third method it goes to exception.

private void M1()
{  
   try
   {
     //some code
     //calling M2()
     //some code
   }
   catch(Exception ex)
   {
      MessageBox.Show(ex.Message);
   }
}
private void M2()
{  
   try
   {
     //some code
     //calling M3()
     //some code
   }
   catch(Exception ex)
   {
      throw ex;
   }
}
private void M3()
{  
   try
   {
     //some code
     //Error Occur
     //some code
   }
   catch(Exception ex)
   {
      throw ex;
   }
}

Now it goes directly to M1() method and shows Exception. And the another method is

private void M1()
{  
   try
   {
     //some code
     //calling M2()
     //some code
   }
   catch(Exception ex)
   {
      MessageBox.Show(ex.Message);
   }
}
private void M2()
{  
   try
   {
     //some code
     //calling M3()
     //some code
   }
   catch(Exception ex)
   {
      MessageBox.Show(ex.Message);
      return;
   }
}
private void M3()
{  
   try
   {
     //some code
     //Error Occur
     //some code
   }
   catch(Exception ex)
   {
      MessageBox.Show(ex.Message);
      return;
   }
}

After exception also it execute the code in M2() and in M1().

Which Program is best...,

First of all, don't catch an exception if you don't do anything with it. So this is bad practise: `catch(Exception ex) { throw ex; }`. If you want to keep the original stacktrace, you should at least use `throw` instead of `throw ex`. http://msdn.microsoft.com/en-us/library/seyhszts.aspx and http://stackoverflow.com/questions/4761216/c-throwing-custom-exception-best-practices — Tim Schmelter, Mar 07 '13 at 12:10
None of them. 1) Catching an exception only to re-throw it -> no point, 2) Message boxes in non-UI methods -> bad separation of logic and presentation. — Thorsten Dittmar, Mar 07 '13 at 12:12
Addendum: The reason why catching exceptions only to throw them again is bad practice, is because exception handling is **extremely** slow. — Nolonar, Mar 07 '13 at 12:13
@Nolonar: Exception handling is only extremely slow in debug mode, in release mode it's just slow. — Guffa, Mar 07 '13 at 12:15
don't use throw ex, use only throw. Instead of catching and throwing exception directly catch the exception in the main method (M1), that's better option. — nRk, Mar 07 '13 at 12:18

score 2 · Answer 1 · answered Mar 07 '13 at 12:11

2

There is nothing good or bad design, only your scenario decided the best approach.

If you want to catch the error on M1 then don't write Try .. catch in M2 and M3.

If you want to handle the error in the function where error was raised then put the Try .. catch in same function.

answered Mar 07 '13 at 12:11

Romil Kumar Jain

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2

While I don't really like to end up in a discussion here, I strongly disagree: There *is* such a thing as "bad design"! – Thorsten Dittmar Mar 07 '13 at 12:14
If i have more more methods i want to know where the error is then what i want to do... – sree aneev Mar 07 '13 at 12:21
do you want this for logging/auditing purpose? – Romil Kumar Jain Mar 07 '13 at 12:22
No sir, Just for learning how to use try catch – sree aneev Mar 07 '13 at 12:23
Error is catched in a function, if you want to minimize the impact of error or perform some other operation. the try and catch will suppress the error in the function where it raised. – Romil Kumar Jain Mar 07 '13 at 12:26
for suppressing the error only we want to use try and catch.., – sree aneev Mar 07 '13 at 12:34
yes, you want to log error in files or minimize the damage due to this error. – Romil Kumar Jain Mar 07 '13 at 12:38

Exception Handling in C# using try catch

1 Answers1