error LNK2001: unresolved external symbol "*******__cdecl****"
这种连接错误是在C++文件里调用C程序导致的，解决方法是:
In the header file for C files (ANSI C), add the following
prior to and after function prototypes.
#ifdef __cplusplus
extern "C"
{
#endif
//////////////////////
code.....
/////////////////////
#ifdef __cplusplus
}
#endif