c# - 无法让 MFC dll 函数在 .net 中运行

Question

我正在尝试创建一个简单的 MFC DLL，导出其函数并在 C# .net 项目中使用在下面的代码中，我在 DLL 中有两种方法，我已经将发帖者的建议用于原始问题。我重新发布当前代码，我收到错误

{ "Unable to find an entry point named '_Worker_Create@0'in DLL 'C:\Users\mspath\Documents\MDS_SIMCA\DevSIMCA_Dll\TestDLL\Debug\MFClib.dll'.":"" }

我已经使用 dumpbin.exe 获得了正确的错位名称。

MFC 动态链接库.cpp

   #include "stdafx.h"
    #include "Worker.h"

    Worker::Worker(void)
    {
    }

    Worker::~Worker(void)
    {
    }

    int Worker::GetInteger()
    {
        return 44;
    }

    int Worker::DoMath(int iOne, int iTwo)
    {
        return iOne * iTwo;
    }

MFC 动态链接库.h

类 worker {民众: worker (无效)； ~ worker (无效)；

static int GetInteger ();
static int DoMath (int iOne, int iTwo);

};

MFCLib.cpp

extern "C"
{
    __declspec(dllexport) void * __stdcall Worker_Create()
    {
        return new Worker();
    }

    __declspec(dllexport) void  * __stdcall Worker_Destroy(Worker * instance)
    {
        delete instance;
        instance = 0;
        return instance;
    }

    __declspec(dllexport) int __stdcall Worker_DoMath(Worker * instance, int i, int j)
    {
        return instance->DoMath(i, j);
    }
}

C#.net

   public partial class MainWindow : Window
    {
/*
 *          from dumbin.exe /exports:
 *          
          1    0 00011519 _Worker_Create@0 = @ILT+1300(_Worker_Create@0)
          2    1 00011230 _Worker_Destroy@4 = @ILT+555(_Worker_Destroy@4)
          3    2 000110D2 _Worker_DoMath@12 = @ILT+205(_Worker_DoMath@12)
*/
        [DllImport("C:\\Users\\mspath\\Documents\\MDS_SIMCA\\DevSIMCA_Dll\\TestDLL\\Debug\\MFClib.dll",
                EntryPoint = "_Worker_Create@0",
                ExactSpelling = false,
                CallingConvention = CallingConvention.StdCall)]
        public extern static IntPtr Worker_Create();

        [DllImport("C:\\Users\\mspath\\Documents\\MDS_SIMCA\\DevSIMCA_Dll\\TestDLL\\Debug\\MFClib.dll",
                EntryPoint = "_Worker_Destroy@4",
                CallingConvention = CallingConvention.StdCall)]
        public extern static IntPtr Worker_Destroy(IntPtr iptr);

        [DllImport("C:\\Users\\mspath\\Documents\\MDS_SIMCA\\DevSIMCA_Dll\\TestDLL\\Debug\\MFClib.dll",
                EntryPoint = "_Worker_DoMath@12",
                CallingConvention = CallingConvention.StdCall)]
        public extern static int Worker_DoMath(IntPtr instance, int i, int j);

        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            IntPtr instance = Worker_Create();

            int i = Worker_DoMath(instance, 4, 2);

            Worker_Destroy(instance);
        }
    }

Answer 1

您必须在 C++ 类的外部声明外部“C 风格”函数。将调用通过管道传递给类的一种方法:

__declspec(dllexport) int DoMath (int iOne, int iTwo)
{
    Worker* worker = new Worker();
    int i = worker-> DoMath(iOne, iTwo);
    delete worker;
    return i;
}

或者将您的 C++ 类转换为 C++/CLI 类，并将库导入为托管 库而不是非托管 库。

免责声明:我的 C++ 生锈了，所以我可能在语法和/或适当的内存管理上略有偏差。