How to detect WFAPI is installed on the system and functioning properly

# include <tchar.h>

# include <stdio.h>

# include "wfapi.h"

/*Change this to WFAPI for 32 bit*/

# define WFAPILIB _T("WFAPI64DLL")`

/* WFFreeMemory function pointer */

typedef VOID ( WINAPI *PFnWFFreeMemory) (PVOID);

/* WFSendMessage function pointer*/

typedef BOOL ( WINAPI *PFnWFSendMessage)

(IN HANDLE hServer,

IN DWORD SessionId,

IN LPWSTR pTitle,

IN DWORD TitleLength,

IN LPWSTR pMessage,

IN DWORD MessageLength,

IN DWORD Style,

IN DWORD Timeout,

OUT DWORD* pResponse,

IN BOOL bWait);

/* WFQuerySessionInformation function pointer*/

typedef BOOL ( WINAPI *PFnWFQuerySessionInformation)

(IN HANDLE hServer,

IN DWORD SessionId,

IN WF_INFO_CLASS WFInfoClass,

OUT LPWSTR* ppBuffer,

OUT DWORD* pBytesReturned);

/* WFEnumerateProcesses function pointer*/

typedef BOOL ( WINAPI *PFnWFEnumerateProcesses)

(IN HANDLE hServer,

IN DWORD Reserved,

IN DWORD Version,

OUT PWF_PROCESS_INFOW *ppProcessInfo,

OUT DWORD *pCount);

/* WFEnumerateSessions function pointer*/

typedef BOOL ( WINAPI *PFnWFEnumerateSessions)

(IN HANDLE hServer,

IN DWORD Reserved,

IN DWORD Version,

OUT PWF_SESSION_INFOW* ppSessionInfo,

OUT DWORD* pCount);

/*UNICODE version of method call : For ANSI replace W with A */

PFnWFSendMessage pFnWFSendMessage = NULL;

char aWFSendMessage[] = "WFSendMessageW";

PFnWFEnumerateSessions pFnWFEnumerateSessions = NULL;

char aWFEnumerateSessions[] = "WFEnumerateSessionsW";

PFnWFEnumerateProcesses pFnWFEnumerateProcesses = NULL;

char aWFEnumerateProcesses[] = "WFEnumerateProcessesW";

PFnWFQuerySessionInformation pFnWFQuerySessionInformation = NULL;

char aWFQuerySessionInformation[] = "WFQuerySessionInformationW";

PFnWFFreeMemory pFnWFFreeMemory = NULL;

char aWFFreeMemory[] = "WFFreeMemory";

VOID freeWFMemory(void * pVoid)

{

if (pVoid != NULL)

{

pFnWFFreeMemory(pVoid);

pVoid = NULL;

}

}

int _tmain(int argc, _TCHAR* argv[])

{

HINSTANCE dll;

DWORD sessionid = WF_CURRENT_SESSION;

LPWSTR pztitle =_T("WFAPI");

LPWSTR pzmessage =_T("WFAPI Test message");

DWORD resp = 0;

/* Trying to load WFAPI dll , expecting to have the library in system search path as set in environment variable ,you can also change this to a specific location */

dll = LoadLibrary(WFAPILIB);

if (dll == NULL )

{

_tprintf(_T("Could not locate WFAPI on the system...\n"));

return 0;

}

else

{

_tprintf(_T("Found WFAPI on the machine...\n"));

}

pFnWFSendMessage = (PFnWFSendMessage) GetProcAddress(dll,
aWFSendMessage);

pFnWFFreeMemory = (PFnWFFreeMemory) GetProcAddress(dll, aWFFreeMemory);

pFnWFEnumerateSessions = (PFnWFEnumerateSessions) GetProcAddress(dll,
aWFEnumerateSessions);

pFnWFEnumerateProcesses = (PFnWFEnumerateProcesses) GetProcAddress(dll,
aWFEnumerateProcesses);

pFnWFQuerySessionInformation = (PFnWFQuerySessionInformation)
GetProcAddress(dll, aWFQuerySessionInformation);

/* Checking for Non NULL function pointer */

if((pFnWFSendMessage != NULL) &&

(pFnWFFreeMemory != NULL) &&

(pFnWFEnumerateSessions != NULL) &&

(pFnWFEnumerateProcesses != NULL) &&

(pFnWFQuerySessionInformation != NULL))

{

/* Send message to current session and current server */

if(pFnWFSendMessage(WF_CURRENT_SERVER_HANDLE,

sessionid,

pztitle,

(_tcslen(_T("WFAPI")) + 1) *sizeof(TCHAR),pzmessage,
(_tcslen(_T("WFAPI Test message")) + 1) * sizeof(TCHAR),

MB_OK,

0 ,

&resp,

FALSE))

{

_tprintf(_T("Message could be send using WFAPI API\...\n"));

}

}

FreeLibrary(dll);

return 0;

}