// Win32Project1.cpp : Defines the exported functions for the DLL application.

#include "stdafx.h"

struct Book
{
     int Price;
     char* Name;
};

extern "C" __declspec(dllexport) void MyText(LPCTSTR text)
{
     ::MessageBox(NULL, text, "My Message1", MB_OK);
}

extern "C" __declspec(dllexport) void MyText2(Book* pBook)
{
     ::MessageBox(NULL, pBook->Name, "My Message2", MB_OK);
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Runtime.InteropServices;
namespace ConsoleApplication1
{
     [StructLayout(LayoutKind.Sequential)]
     struct Book
     {
          public int Price;
          public string Name;
     }

     class Program
     {
          [DllImport("Win32Project1.dll", CallingConvention = CallingConvention.Cdecl)]
          public static extern void MyText(string text);

          [DllImport("Win32Project1.dll", CallingConvention = CallingConvention.Cdecl)]
          public static extern void MyText2(ref Book book);

          static void Main(string[] args)
          {
               MyText("Hello");

               Book book = new Book();
               book.Price = 62;
               book.Name = "Властелин Колец";
               MyText2(ref book);
          }
     }
}