Visual Studio DllNotFoundException-Collection of common programming errors

    public const string LIB_GVC = "gvc.dll";
    public const string LIB_GRAPH = "graph.dll";
    public const int SUCCESS = 0;


    [DllImport(LIB_GVC)]
    public static extern IntPtr gvContext();

Later, in the main method I call gvContext() and it throws the DllNotFoundException. In my project, I have gone into the Project->Properties and set the reference paths so that I have a folder called “resources” which contains all my DLLs including gvc.dll. I thought this would do the trick but it didn’t. What do I need to do?

Note: I cannot use Add Reference as I normally would, I realize that this behavior is normal considering Graphviz is not a C# library. I’m also a bit fuzzy on terminology, why is it called an “unmanaged DLL”? It seems to be because it wasn’t compiled from C# code but is that true/not the whole story?

I’m following this tutorial if it helps clarify anything.