通过LoadLibraryA 和 GetProcAddress，动态调用无需配置链接库lib和相关的头文件配置。下面介绍一个例子的实现

头文件：
#pragma once

class MyAdd

{

public:

    MyAdd();

    virtual ~MyAdd();

    int add(int a, int b);

    float add(float a, float b);

};
源文件：

#include "MyAdd.h"

MyAdd::MyAdd()

{

}

MyAdd::~MyAdd()

{

}
int MyAdd::add(int a, int b)

{

    return a + b;

}

float MyAdd::add(float a, float b)

{

    return a + b;

}

头文件：
#include <stdlib.h>

#include "MyAdd.h"

#include "add_api.h"

int csvMyAddGetInstance(void ** ppHandle)

{

    MyAdd* p = new MyAdd();

    *ppHandle = p;

    return ;

}

int csvMyAddReleaseInstance(void * ppHandle)

{

    MyAdd* p = (MyAdd*)(ppHandle);

    if (p != NULL)

    {

        delete p;

        p = NULL;

    }

    return ;

}

int csvMyAddaddInt(void ** ppHandle, int a, int b)

{

    MyAdd* p = (MyAdd*)(ppHandle);

    if (p == NULL) return INT_MIN;

    return a + b;

}

float csvMyAddaddFloat(void ** ppHandle, float a, float b)

{

    MyAdd* p = (MyAdd*)(ppHandle);

    if (p == NULL) return INT_MIN;

    return a + b;

}

源文件：
#ifndef CSV_ADD_API_H

#define CSV_ADD_API_H

#ifdef CSVADDAPI_LIB
  #define CSVADDAPI_LIB_EXPORT extern "C" __declspec(dllexport)
  #else
  #define CSVADDAPI_LIB_EXPORT extern "C" __declspec(dllimport)
  #endif

CSVADDAPI_LIB_EXPORT int csvMyAddGetInstance(void ** ppHandle);

CSVADDAPI_LIB_EXPORT int csvMyAddReleaseInstance(void * ppHandle);

CSVADDAPI_LIB_EXPORT int csvMyAddaddInt(void ** ppHandle, int a, int b);

CSVADDAPI_LIB_EXPORT float csvMyAddaddFloat(void ** ppHandle, float a, float b);

#endif //CSV_ADD_API_H

#include <iostream>

#include <stdlib.h>

#include <string>

#include<stdio.h>

#include <windows.h>

using namespace std;

/*通过LoadLibraryA 和 GetProcAddress，动态调用无需配置链接库lib和相关的头文件*/

typedef int(*MyAddGetInstance)(void **ppHandle);              //定义类型：获取加法类的函数指针

typedef int(*MyAddReleaseInstance)(void *ppHandle);           //定义类型：声明释放加法类的函数指针

typedef int(*MyAddAddInt)(void **ppHandle, int a, int b);     //定义类型：声明整数的加法函数指针

int main(int argc, char** argv)

{

    /*导入DLL库*/

    string dll_path = "MyDll.dll";

    HINSTANCE phandle = LoadLibraryA(dll_path.c_str());

    /*获取 DLL库内部的函数句柄*/

    MyAddGetInstance csvMyAddGetInstance;

    csvMyAddGetInstance = (MyAddGetInstance)GetProcAddress(phandle, "csvMyAddGetInstance");

    MyAddReleaseInstance csvMyAddReleaseInstance;

    csvMyAddReleaseInstance = (MyAddReleaseInstance)GetProcAddress(phandle, "csvMyAddReleaseInstance");

    MyAddAddInt myAddAddInt;

    myAddAddInt = (MyAddAddInt)GetProcAddress(phandle, "csvMyAddaddInt");

    /*调用函数*/

    void* pinst = NULL;

    csvMyAddGetInstance(&pinst);

    int res = myAddAddInt(&pinst, , );

    csvMyAddReleaseInstance(pinst);

    cout << res << endl;

    system("pause");

    return  ;

}