C# dll file function access from python code

Question

My aim is to access C# dll file function from python script ctypes library. My C# code is:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using RGiesecke.DllExport;
    using System.Runtime.InteropServices;

    namespace ConsoleApp1
    {
       [ComVisible(true)]
       public class Program
      {
    [DllExport("MyFunctionName", CallingConvention = CallingConvention.Cdecl)]
    [return: MarshalAs(UnmanagedType.LPWStr)]
    public static string MyFunctionName([MarshalAs(UnmanagedType.LPWStr)] string iString)
    {
        return "hello world i'm " + iString;
    }

    [DllExport("Add",CallingConvention = CallingConvention.Cdecl)]
    public static int Add(int a, int b)
    {
        return a + b;
    }
    [DllExport(CallingConvention = CallingConvention.Cdecl)]
    static public int Subtract(int a, int b)
    {
        return a - b;
    }
    [DllExport(CallingConvention = CallingConvention.Cdecl)]
    static public int Multiply(int a, int b)
    {
        return a * b;
    }
    [DllExport(CallingConvention = CallingConvention.Cdecl)]
    static public int Divide(int a, int b)
    {
        return a / b;
    }

    static void Main(string[] args)
    {
        //Console.Write(Add(2,3));
    }
}

}

and python code is :

    import ctypes
    a=ctypes.cdll.LoadLibrary('File Location')
    a.MyFunctionName("a")

But I am getting error AttributeError: function 'MyFunctionName' not found

How I can resolve the error as the I can't access the functions included in dll file ?

Answer 1

Maybe this helps. From RGiesecke.DllExport documentation: - You have to set your platform target to either x86, ia64 or x64. AnyCPU assemblies cannot export functions . - The export name defaults to the method name and the calling convention to stdcall. If that's all what you want, you can just use [DllExport] without parameters. - You cannot put your exports in generic types or export generic methods. (The CLR wouldn't know what type parameters to use)