FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

David M. Kean — Sat, 10 Jun 2006 09:00:35 GMT

The ApplicationException documentation has now been fixed: http://msdn2.microsoft.com/en-US/library/system.applicationexception(VS.80).aspx.

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

David M. Kean — Wed, 12 Apr 2006 21:26:17 GMT

Just had a look, and a customer has already filed it:

http://lab.msdn.microsoft.com/ProductFeedback/viewfeedback.aspx?feedbackid=ffeda598-cf85-4076-8683-1d6b6607d5c3

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

David M. Kean — Wed, 12 Apr 2006 21:04:59 GMT

Peter,

The Microsoft Design Guidelines (as linked above) are the correct docs. I will file a bug internally regarding the ApplicationException docs.

Existing code both internally and externally derive from ApplicationException. As it is a breaking change to change the base of a class (especially an Exception), it can't be marked obsolete.

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

Peter — Wed, 12 Apr 2006 20:53:32 GMT

The Product Feedback link is broken (gives me a generic error with this URL: http://lab.msdn.microsoft.com/productfeedback/Error.aspx?errtype=http&errno=500) so I'll enter it here instead.

These new recommendations--"don't throw ApplicationException and don't derive from it"--coupled with the fact that ApplicationException is by definition not something the Framework will derive/throw, begs the question: What's the ApplicationException class to be used for now? And if the answer is "nothing," why isn't it marked as obsolete, since the recommendation in Brad's entry came out nearly 18 months ahead of .NET 2.0?

And when you say "several outdated documents floating around on the web," these include the official Microsoft .NET Framework documentation:

http://msdn2.microsoft.com/en-US/library/system.applicationexception(VS.80).aspx

I can certainly understand the reasons for reversing your advice regarding ApplicationException, I just wonder why the FxCop and a couple other blogs are the only ones that say so, and not more high-profile sources like the docs.

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

David M. Kean — Thu, 06 Apr 2006 16:51:37 GMT

Fixed and Fixed. ;)

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

mcgurk — Thu, 06 Apr 2006 16:13:28 GMT

Rock on! Where can I get aholt of the bass class library? I've got some killer riffs I want to implement!

re: FAQ: Why do some sources recommend extending ApplicationException while FxCop does not? [Michael Fanning, David Kean]

JaredPar MSFT — Thu, 06 Apr 2006 10:32:47 GMT

Your link to "Catching and throwing Standard Exception Types" appears to be broken.