Exception propagation in C#

Question

Suppose I have three functions doA(), doB(), and doC() in a C# program where I know that doA() will call doB() which in turn calls doC().

Since doC() has to interact with a database, I know that it could very well generate exceptions that it won't be able to resolve that need to be brought to the user's attention. At the moment, I have the code which might throw the error in a try / catch blow in doC() and then the call to doC() in doB() in another try / catch and similarly the call to doB() in doA() in try / catch block. This allows me to just use throw; to kick the exception up to doA() where something can reasonably be done to display this to the user.

This seems a little like overkill though. I am wondering if since I don't plan on dealing with the exception in doB() or doC() if I can just get rid of the try / catch blocks there.

Assuming there are no finally blocks involved, what is the best practice for dealing with situations like this?

Answer 1

If your catch blocks are just like this:

catch (Exception)
{
    throw;
}

then they are pointless indeed. You're not really handling the exception - don't bother with try/catch at all.

Personally I have very few try/catch blocks in my code - and although there are plenty of implicit try/finally blocks, most are due to using statements.

Answer 2

Yes I would get rid of the try/catch blocks - just let the exception propagate up to the top level and then catch it there. Catching an exception just to rethrow with throw; is simply not useful, although the following variation is actually harmful as it destroys the stack trace information:

catch (Exception exception)
{
    throw exception;
}