won't catch my custom exception

  • Thread starter Thread starter rodchar
  • Start date Start date
R

rodchar

hey all,

i have a very simple custom exception class:

public class EmptyRecordException : Exception
{
string message;

public override string Message
{
get
{
return message;
}
}

public EmptyRecordException(string message)
{
this.message = message;
}
}


Here's how i try to throw it:

public void ThrowMockException()
{
throw new EmptyRecordException("message from c2");
}



i'm trying to catch it this way:

catch (EmptyRecordException ex)
{
throw ex.Message;
}

but it is giving me an error saying:
The type caught or thrown must be derived from System.Exception

any ideas?

thanks,
rodchar
 
Hi,

the error is in the line:

throw ex.Message;

Here you want to throw a System.String instead of an object of type
System.Exception...

greets and sorry for my bad english, Wolfgang Kluge
http://gehirnwindung.de/
http://klugesoftware.de/


----- Original Message -----
From: "rodchar" <[email protected]>
Newsgroups: microsoft.public.dotnet.languages.csharp
Sent: Thursday, July 02, 2009 4:22 PM
Subject: Re: won't catch my custom exception
 
rodchar used his keyboard to write :
can i please ask why?
Click to expand...

The "it" that was giving the error apparently was the compiler (not the
runtime). And the line it was complaining about was not the declaration
of your exception, but the "throw ex.Message" statement.
And the compiler was complaining because Message is a string, not an
exception. So you can solve the issue by just using "throw ex".
and does my custom exception class look correct?
Click to expand...

Looks ok, but you don't need to override Message (unless you have other
plans). Rewrite the constructor as:

public EmptyRecordException(string message)
: base(message)
{
}

The ": base(message)" calls the base constructor, which will set the
Message property for you.

Hans Kesting
 
thanks everyone for the help,
rod.

Wolfgang Kluge said:
Hi,

the error is in the line:

throw ex.Message;

Here you want to throw a System.String instead of an object of type
System.Exception...

greets and sorry for my bad english, Wolfgang Kluge
http://gehirnwindung.de/
http://klugesoftware.de/


----- Original Message -----
From: "rodchar" <[email protected]>
Newsgroups: microsoft.public.dotnet.languages.csharp
Sent: Thursday, July 02, 2009 4:22 PM
Subject: Re: won't catch my custom exception
Click to expand...
 
rodchar said:
thanks everyone for the extra insight, i appreciate it much,
Click to expand...

C# is not like C++ - you can only throw instances of Exception and
sub classes (or null) - you can not throw instances of an arbitrary
type.

Arne
 
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