C++通过LoadLibrary的方式调用C封装的dll

古城微笑少年丶 2022-12-05 12:09 229阅读 0赞

# 编写DLL代码 #

## 新建工程 ##

新建空项目工程

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70][]

点击确定。然后右键项目选择新建项。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 1][]

再次选择新建项，选中C++文件，将其改为MySocketClient.c，然后选择添加。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 2][]

到这里，新建工程就完成了。

![20200910105252823.png][]

然后右键项目，选择属性 将配置类型改为动态库(.dll)

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 3][]

## 编写头文件MySocketClient.h ##

\#ifndef \_INC\_MYSOCKETCLIENT\_H\_

\#define \_INC\_MYSOCKETCLIENT\_H\_

\#define Import\_SSS

\#ifdef Import\_SSS

\#define API \_declspec(dllexport)

\#else

\#define API \_declspec(dllimport)

\#endif

\#ifdef \_cplusplus//extern"C" 来告诉编译器:这是一个用C写成的库文件，请用C的方式来链接它们。

extern "C" \{

\#endif // \_cplusplus

API//导出函数，让外界调用。

int socketClient\_Init(void \*\*handle);

API

int socketClient\_Send(void \*handle, unsigned char \*buf, int buflen);

API

int socketClient\_Recv(void \*handle, unsigned char \*buf, int \*buflen);

API

int socketClient\_Destory(void \*handle);

\#ifdef \_cplusplus

\#endif // \_cplusplus

\#endif //\_INC\_MYSOCKETCLIENT\_H\_

## 编写MySocketClient.c ##

\#define *\_CRT\_SECURE\_NO\_WARNINGS*

\#include <stdlib.h>

\#include <string.h>

\#include <stdio.h>

\#include "MySocketClient.h"

typedef struct \_Sck\_Handle

char version\[16\];

char ip\[16\];

int port;

unsigned char \*p;

int len;

\}Sck\_Handle;//定义Handle的结构体。

int socketClient\_Init(void \*\*handle)

int ret = 0;

Sck\_Handle \*tmpHandle = *NULL*;

if (handle == *NULL*)

ret = -1;

*printf*("\[socketClient\_Init\] err %d handle=NULL \\n", ret);

return ret;

tmpHandle = (Sck\_Handle \*)*malloc*(sizeof(Sck\_Handle));

if (tmpHandle == *NULL*)

ret = -2;

*printf*("\[socketClient\_Init\] err:%d malloc err \\n", ret);

*memset*(tmpHandle, 0, sizeof(Sck\_Handle));//初始化结构体。

*strcpy*(tmpHandle\->version, "1.0.0.1");

*strcpy*(tmpHandle\->ip, "192.168.12.121");

tmpHandle\->port = 11111;

\*handle = tmpHandle;

return ret;

socket报文发送

//\_\_declspec(dllexport)

int socketClient\_Send(void \*handle, unsigned char \*buf, int buflen)

int          ret = 0;

Sck\_Handle   \*tmpHandle = *NULL*;

if (handle == *NULL* || buf == *NULL* || buflen <= 0)

ret = -2;

*printf*("func socketclient\_send() err :%d  (handle == NULL ||  buf==NULL || buflen <=0 ) \\n", ret);

return ret;

tmpHandle = (Sck\_Handle \*)handle;

tmpHandle\->len = buflen;

tmpHandle\->p = (unsigned char \*)*malloc*(buflen);

if (tmpHandle\->p == *NULL*)

ret = -2;

*printf*("func socketclient\_send() err :%d  malloc len:%d \\n", ret, buflen);

return ret;

*memcpy*(tmpHandle\->p, buf, buflen); //数据的缓存到内存

*printf*("接收到发送数据是%s \\n", tmpHandle\->p);

return ret;

socket报文接受

//\_\_declspec(dllexport)

int socketClient\_Recv(void \*handle, unsigned char \*buf, int \*buflen)

int          ret = 0;

Sck\_Handle   \*tmpHandle = *NULL*;

if (handle == *NULL* || buf == *NULL* || buflen == *NULL*)

ret = -2;

*printf*("func socketclient\_recv() err :%d  (handle == NULL ||  buf==NULL || buflen==NULL ) \\n", ret);

return ret;

tmpHandle = (Sck\_Handle \*)handle;

*memcpy*(buf, tmpHandle\->p, tmpHandle\->len);

\*buflen = tmpHandle\->len; //间接赋值  告诉调用者 收到的数据的长度

*printf*("数据长度是%d \\n", tmpHandle\->len);

return ret;

socket环境释放

//\_\_declspec(dllexport)

int socketClient\_Destory(void \*handle)

int          ret = 0;

Sck\_Handle   \*tmpHandle = *NULL*;

if (handle == *NULL*)

return \-1;

tmpHandle = (Sck\_Handle \*)handle;

if (tmpHandle\->p != *NULL*)

*free*(tmpHandle\->p); //释放结构体 成员域的 指针所指向的内存空间

*free*(tmpHandle); //释放结构体内存

return 0;

然后右键编译工程。在Debug文件夹下面就可以看到生成的dll

# 调用DLL #

新建C++控制台应用程序

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 4][]

新建完成后，将编译好的dll文件、lib文件和h文件放到工程下面。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 5][]

右键项目属性，将字符集改为使用多字节字符集。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 6][]

下面是调用dll的代码。

\#define  *\_CRT\_SECURE\_NO\_WARNINGS*

\#include <stdio.h>

\#include <windows.h>

\#include <iostream>

using namespace *std*;

//定义指针函数

typedef int(\*SOCLETCLIENT\_INIT)(void \*\*handle);

typedef int(\*SOCKETCLIENT\_SEND)(void \*handle, unsigned char \*buf, int buflen);

typedef int(\*SOCKETCLIENT\_RECV)(void \*handle, unsigned char \*buf, int \*buflen);

typedef int(\*SOCKETCLIENT\_DESTORY)(void \*handle);

int main()

*HINSTANCE* hInstance;

hInstance = *LoadLibrary*("MySocketClient.dll");

SOCLETCLIENT\_INIT socketClient\_Init= (SOCLETCLIENT\_INIT)*GetProcAddress*(hInstance, "socketClient\_Init");

SOCKETCLIENT\_SEND socketClient\_Send=(SOCKETCLIENT\_SEND)*GetProcAddress*(hInstance, "socketClient\_Send");;

SOCKETCLIENT\_RECV socketClient\_Recv= (SOCKETCLIENT\_RECV)*GetProcAddress*(hInstance, "socketClient\_Recv");;

SOCKETCLIENT\_DESTORY socketClient\_Destory= (SOCKETCLIENT\_DESTORY)*GetProcAddress*(hInstance, "socketClient\_Destory");;

unsigned char buf\[1024\];

int buflen;

unsigned char out\[1024\];

int outlen;

void \*handle = *NULL*;

int ret = 0;

*strcpy*((char \*)buf, "aaaaAAAAAFFffffffdddddddd");

buflen = 9;

//客户端初始化 获取handle上下

ret = socketClient\_Init(&handle /\*out\*/);

if (ret != 0)

*printf*("func socketclient\_init() err:%d \\n ", ret);

goto End;

//客户端发报文

ret = socketClient\_Send(handle /\*in\*/, buf /\*in\*/, buflen /\*in\*/);

if (ret != 0)

*printf*("func socketclient\_send() err:%d \\n ", ret);

goto End;

//客户端收报文

ret = socketClient\_Recv(handle /\*in\*/, out /\*in\*/, &outlen/\*in out\*/);

if (ret != 0)

*printf*("func socketclient\_recv() err:%d \\n ", ret);

goto End;

*printf*("接收到的数据长度是%d \\n",outlen);

End:

//客户端释放资源

ret = socketClient\_Destory(handle/\*in\*/);

if (hInstance != *NULL*)

*FreeLibrary*(hInstance);

hInstance = *NULL*;

*printf*("hello...\\n");

*system*("pause");

return 0;

代码链接：[https://download.csdn.net/download/hhhhhhhhhhwwwwwwwwww/12831335][https_download.csdn.net_download_hhhhhhhhhhwwwwwwwwww_12831335]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70]: /images/20221123/51eb3b9600d84e9aa87adeb235250c89.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 1]: /images/20221123/230002808c5a462c97bc70c24b6b9ac7.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 2]: /images/20221123/42074dbce00f4955a40cb7cb38bc00af.png
[20200910105252823.png]: /images/20221123/a9d5e316201242589b0634eb4df9c7fd.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 3]: /images/20221123/2d23e21d32094b6e9112a604bf79d417.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 4]: /images/20221123/d8142274cd2141afb11f21f1d0df3ca0.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 5]: /images/20221123/4b0a995642b843e1b80f4298276aac45.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hoaGhoaGhoaGh3d3d3d3d3d3d3_size_16_color_FFFFFF_t_70 6]: /images/20221123/73a0f13bca4d4ae28afd7e173507a357.png
[https_download.csdn.net_download_hhhhhhhhhhwwwwwwwwww_12831335]: https://download.csdn.net/download/hhhhhhhhhhwwwwwwwwww/12831335