> Hi guys,
> [sorry I posted it on ASP by error]
>
> When bubbling some exception up to some interface handlers
>
> - what is most recommandable:
>
>         Try
>             'some code
>         Catch ex As Exception
>             Throw
>         End Try
> or
>
>         Try
>             'some code
>         Catch ex As Exception
>             Throw ex
>         End Try
> ?
>
>
> - What about I just to want to add some comments in the error message,
> BUT
>   I want to keep ALL the inner exceptions (so that I can recursively
> spit them to the
>   user when I arrive up to the UI ) How do I do that correctly ?
>
>
> - And, is it true that anything after a Throw will be in any case
> ignored ?
>

> pamelaflue***@libero.it wrote:
> > Hi guys,
> > [sorry I posted it on ASP by error]
> >
> > When bubbling some exception up to some interface handlers
> >
> > - what is most recommandable:
> >
> >         Try
> >             'some code
> >         Catch ex As Exception
> >             Throw
> >         End Try
> > or
> >
> >         Try
> >             'some code
> >         Catch ex As Exception
> >             Throw ex
> >         End Try
> > ?
> >
> >
> > - What about I just to want to add some comments in the error message,
> > BUT
> >   I want to keep ALL the inner exceptions (so that I can recursively
> > spit them to the
> >   user when I arrive up to the UI ) How do I do that correctly ?
> >
> >
> > - And, is it true that anything after a Throw will be in any case
> > ignored ?
> >
>
> You would probably be best served by deriving your own Exception type
> and then when you catch an exception in your Try block, assign it to
> the InnerException of your exception type, either using the constructor
> or just assigning it.  That should preserve the stack trace.  In my
> contrived example below, the exception pointed to by ex gets assigned
> to the Inner Exception property of the MyNewException class.
>
>      Try
>           'some code
>      Catch ex As Exception
>           Throw New MyNewExceptionType("Custom message", ex)
>      End Try

> pamelaflue***@libero.it wrote:
>
> > - what is most recommandable:
>
> >         Catch ex As Exception
> >             Throw
>
> > or
>
> >         Catch ex As Exception
> >             Throw ex
>
> /As given/, neither.
> Don't catch an exception unless you intend to do something /useful/ with
> it.  Simply re-throwing it doesn't count as useful.  But this is only
> "sample" code, so ...
>
> If you must re-throw the Exception, just use "Throw".  That retains all
> the Call Stack information contained within the Exception.  "Throw ex"
> loses it.
>
> I would only use "Throw ex" from the entry point of a library, where I
> don't necessarily want the Outside World to know all the innards of my
> code.
>
> > - What about I just to want to add some comments in the error message,
>
> /Don't/ use the Message to store additional information.
> It's far too easy to change a literal in your code and, in doing so,
> break [lots of] code elsewhere that's looking for whatever string was in
> there previously.
>
> Create a Custom Exception class and add your extra properties to that.
>
> HTH,
>     Phill  W.