We have a project with over 500,000 lines of VB.NET that we need to convert to C#. Any recommendations, based on experience, for tools to use? We are using Visual Studio 2008 and we're targeting 3.5 .
Reflector will decompile the IL and produce C# for you, it will be rough, but a decent start.
I've used this site for a while now for some of my smaller conversions. It has been quite reliable.
According to the site, their converter is based off an open source IDE that has the converter built in, so you might try the "source site" as well.
There used to be an add-in to Reflector which creates a complete Visual Studio solution. However, I don't know if it's still available or working, now that Red Gate has taken over Reflector.
Did this eval a while back. You will find a lot of "free" solutions that are horrible at edge cases. This commercial product http://www.tangiblesoftwaresolutions.com is by no means perfect; but, was the best we could find at the time doing real conversion tests. Note: I am speaking only as a customer. If someone has found a solution that in real-world use produces better conversions than this, please let me know.
I would concur with the comment. You have 500,000 of tried and true VB.Net code. Why on earth would you waste any time changing that? No one says that you can't write all new components in C#.
I would consider not worrying about a tool and instead ask yourself, truly, why you are doing this.
The converter from Telerik works well.
http://converter.telerik.com/
http://converter.telerik.com/batch.aspx