Re-throwing an Exception in .NET

Provided by Dave Juth, Senior Systems Architect

The stack trace is helpful when you are debugging your application. What is not readily apparent is the code you put in place may cause the stack trace to be cleared.

It may be typical for you to write the following error handling:

 

   //C#

   try

   {

      // some code executed here

   }

    

   catch (Exception ex)

   {

      throw ex;

   }

 

 

   'VB

   Try

     ' some code here

 

   Catch ex As Exception

     Throw ex

    

   End Try

 

In the above example, the origin of the exception becomes the line "throw ex." This hides the real location of the exception, and makes debugging a guessing game.
The proper way to re-throw an exception is to use the 'Throw' statement with no exception argument.

 

   //C#

   try

   {

      // some code here

   }

    

   catch (Exception ex)

   {

      throw;

   }  

  

  

   'VB

   Try

      ' some code here

    

   Catch

      Throw

    

   End Try