动态调用DLL的方法(宏实现)

来源：互联网发布：flash cs3 mac版编辑：程序博客网时间：2024/06/08 19:03

参考libusb:

#define DLL_DECLARE_PREFIXNAME(api, ret, prefixname, name, args) \

typedef ret (api * __dll_##name##_t)args; \
static __dll_##name##_t prefixname = NULL

#define DLL_STRINGIFY(dll) #dll
#define DLL_GET_MODULE_HANDLE(dll) GetModuleHandleA(DLL_STRINGIFY(dll))
#define DLL_LOAD_LIBRARY(dll) LoadLibraryA(DLL_STRINGIFY(dll))

#define DLL_LOAD_PREFIXNAME(dll, prefixname, name, ret_on_failure) \
do { \
HMODULE h = DLL_GET_MODULE_HANDLE(dll); \
if (!h) \
h = DLL_LOAD_LIBRARY(dll); \
if (!h) { \
if (ret_on_failure) { return LIBUSB_ERROR_NOT_FOUND; } \
else { break; } \
} \
prefixname = (__dll_##name##_t)GetProcAddress(h, \
DLL_STRINGIFY(name)); \
if (prefixname) break; \
prefixname = (__dll_##name##_t)GetProcAddress(h, \
DLL_STRINGIFY(name) DLL_STRINGIFY(A)); \
if (prefixname) break; \
prefixname = (__dll_##name##_t)GetProcAddress(h, \
DLL_STRINGIFY(name) DLL_STRINGIFY(W)); \
if (prefixname) break; \
if(ret_on_failure) \
return LIBUSB_ERROR_NOT_FOUND; \
} while(0)

#define DLL_DECLARE(api, ret, name, args) DLL_DECLARE_PREFIXNAME(api, ret, name, name, args)
#define DLL_LOAD(dll, name, ret_on_failure) DLL_LOAD_PREFIXNAME(dll, name, name, ret_on_failure)
#define DLL_DECLARE_PREFIXED(api, ret, prefix, name, args) DLL_DECLARE_PREFIXNAME(api, ret, prefix##name, name, args)
#define DLL_LOAD_PREFIXED(dll, prefix, name, ret_on_failure) DLL_LOAD_PREFIXNAME(dll, prefix##name, name, ret_on_failure)

example:

DLL_DECLARE(WINAPI, BOOL, HidD_GetAttributes, (HANDLE, PHIDD_ATTRIBUTES));
DLL_DECLARE(WINAPI, VOID, HidD_GetHidGuid, (LPGUID));
DLL_DECLARE(WINAPI, BOOL, HidD_GetPreparsedData, (HANDLE, PHIDP_PREPARSED_DATA *));

DLL_DECLARE(WINAPI, BOOL, HidD_FreePreparsedData, (PHIDP_PREPARSED_DATA));

use:

DLL_LOAD(hid.dll, HidD_GetAttributes, TRUE);
DLL_LOAD(hid.dll, HidD_GetHidGuid, TRUE);
DLL_LOAD(hid.dll, HidD_GetPreparsedData, TRUE);
DLL_LOAD(hid.dll, HidD_FreePreparsedData, TRUE);