How to get the current directory on a class library?

This should work -

string assemblyFile = (
    new System.Uri(Assembly.GetExecutingAssembly().CodeBase)
).AbsolutePath;

The below code worked for me to get the physical path of the Images folder in-class library file.

string fullFilePath = Path.Combine((new System.Uri(Assembly.GetExecutingAssembly().CodeBase)).AbsolutePath.Split(new string[] { "/bin" }, StringSplitOptions.None)[0]
                          , "@/Images/test.png");

I hope, it will help someone.