Write a dll that is accessable from VS 2003 VC++ code

Question

I need to be able to write a DLL in either C# or VC++ that is accessible from code that is written in Visual Studio 2003 VC++. It looks like the code is unmanaged (uses * for pointers) VC++ and this DLL needs to be able to drop right in and be accessed by the current code.

The DLL is an RS232 driver that needs to be able to return an int for an error code and pass back, by reference, some measured values, to the calling program.

Will I even be able to write this in C#? If not, I only have access to Visual Studio 2005 or 2008. Will I be able to write my code in either, and will that DLL be able to be called from the current code base? Or do I have to go looking on ebay for a copy of VS 2003?

Answer 1

An unmanaged DLL authored in C/C++ in VS2008/2005 should work just fine with invoking code in a VS2003 C/C++ project. It's also likely the path of least resistance. If your DLL references other DLL's that aren't likely to be available with VS2003, make sure to either re-distribute them if you can, or link statically otherwise.

A managed DLL is also possible, but will require a little bit of glue code to bridge the managed/unmanaged gap. Make sure to target the .NET runtime version that VS2003 supports (1.1).