Is it ok to derive from System.ArgumentException?

Question

If I have a method that checks the validity of its arguments, is it ok to throw my own custom exceptions derived from System.ArgumentException? I am asking because ArgumentException is itself derived from System.SystemException and I am seeing conflicting guidelines as to whether an application should derive from SystemException. (Albeit indirectly, deriving from ArgumentException is still tantamount to deriving from SystemException.)

I see lots of guidelines saying don't derive from ApplicationException, but derive from Exception instead. I'm happy with that. What I'm not sure about is whether it's ok to derive from SystemException too.

If I shouldn't derive from SystemException, then what should I derive my "invalid argument" exception classes from?

Answer 1

The MSDN page about Best Practices for Handling Exceptions says

Throw an ArgumentException or a class derived from ArgumentException if invalid parameters are passed.

So i would say it's ok and even recommended.

Answer 2

One benefit of deriving from System.ArgumentException is that catch(System.ArgumentException) blocks will be able to handle your custom exception type as well as System.ArgumentException. This may or may not be what you want.