本文给出了一种方法。基本思想是，写一个 wrapper文件，把 C++类封装起来，对外只提供C语言的接口，和 C++i相关的都在 wrapper的实现文件里实现。
1. apple.h
#ifndef __APPLE_H__
#define __APPLE_H__
class Apple
{
public:
Apple();
int GetColor(void);
void SetColor(int color);
private:
int m_nColor;
};
#endif
apple.cpp
#include "apple.h"
Apple::Apple() : m_nColor(0)
{
}
void Apple::SetColor(int color)
{
m_nColor = color;
}
int Apple::GetColor(void)
{
return m_nColor;
}
2. AppleWrapper.h
#ifndef _APPLE_WRAPPER_H__
#define _APPLE_WRAPPER_H_
#ifdef __cplusplus
extern "C" {
#endif
struct tagApple; // Warning: 不能使用 extern 修饰
extern struct tagApple *GetInstance(void);
extern void ReleaseInstance(struct tagApple **ppInstance);
extern void SetColor(struct tagApple *pApple, int color);
extern int GetColor(struct tagApple *pApple);
#ifdef __cplusplus
};
#endif
#endif
AppleWrapper.cpp
#include "AppleWrapper.h"
#include "apple.h"
#ifdef __cplusplus
extern "C" {
#endif
struct tagApple
{
Apple apple;
};
struct tagApple *GetInstance(void)
{
return new struct tagApple;
}
void ReleaseInstance(struct tagApple **ppInstance)
{
delete *ppInstance;
*ppInstance = 0;
}
void SetColor(struct tagApple *pApple, int color)
{
pApple->apple.SetColor(color);
}
int GetColor(struct tagApple *pApple)
{
return pApple->apple.GetColor();
}
#ifdef __cplusplus
};
#endif
3. test.c
#include "AppleWrapper.h"
#include
#include
#include
#include
int main(void)
{
struct tagApple * pApple;
pApple = GetInstance();
SetColor(pApple, 1);
printf("color = %d\n", GetColor(pApple));
ReleaseInstance(&pApple);
assert(pApple == 0);
return 0;
}
可以用 GCC编译：
g++ -g -c apple.cpp AppleWrapper.cpp
gcc -g test.c -o test AppleWrapper.o apple.o -lstdc++
其实， wrapper里的 struct 完全可以不要，定义一个 handle更好：
AppleWrapper.h
#ifndef _APPLE_WRAPPER_H__
#define _APPLE_WRAPPER_H_
#ifdef __cplusplus
extern "C" {
#endif
extern int GetInstance(int * handle);
extern void ReleaseInstance(int *handle);
extern void SetColor(int handle, int color);
extern int GetColor(int handle);
#ifdef __cplusplus
};
#endif
#endif
AppleWrapper.cpp
#include "AppleWrapper.h"
#include "apple.h"
#include
#ifdef __cplusplus
extern "C" {
#endif
static std::vector
int GetInstance(int * handle)
{
g_appleVector[0] = new Apple; // Error: Segmentation fault (core dumped)
*handle = 0;
return 1;
}
void ReleaseInstance(int *handle)
{
delete g_appleVector[*handle];
*handle = -1;
}
void SetColor(int handle, int color)
{
g_appleVector[handle]->SetColor(color);
}
int GetColor(int handle)
{
return g_appleVector[handle]->GetColor();
}
#ifdef __cplusplus
};
#endif
test.c
#include "AppleWrapper.h"
#include
#include
#include
#include
int main(void)
{
int handle = -1;
GetInstance(&handle);
SetColor(handle, 1);
printf("color = %d\n", GetColor(handle));
ReleaseInstance(&handle);
assert(handle == -1);
return 0;
}
转自 https://blog.csdn.net/caspiansea/article/details/9676153