c#调用c++写成的dll文件

  c#调用c++写成的dll文件 
首先是c++写的声明文件

// Inclusion guard
#ifndef _DLLTUT_DLL_H_
#define _DLLTUT_DLL_H_

// Make our life easier, if DLL_EXPORT is defined in a file then DECLDIR will do an export
// If it is not defined DECLDIR will do an import
#if defined DLL_EXPORT
#define DECLDIR __declspec(dllexport)
#else
#define DECLDIR __declspec(dllimport)
#endif

// Specify "C" linkage to get rid of C++ name mangeling
extern "C"
{
     // Declare 2 functions
     DECLDIR int Add( int a, int b );
     DECLDIR void Function( void );
}

// End the inclusion guard
#endif
测试程序的目录结构



测试代码c#

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

namespace ConsoleApplication30
{
     class Program
     {
         static void Main(string[] args)
         {
             test.Function();

             Console.WriteLine("result: " + test.Add(2, 3).ToString());

             Console.ReadLine();
         }
     }
     class test
     {
         [DllImport("..\\..\\lib\\DLLTest.dll")]
         public static extern   void Function(); 

         [DllImport("..\\..\\lib\\DllTest.dll")]
         public static extern int Add(int i,int j);
     }
}