Windows Calls

The prototype for the HLLAPI calls is defined as follows:

VOID FAR PASCAL
WinHLLAPI (LPWORD lpwFunction, LPBYTE lpbyString, LPWORD lpwLength, LPWORD lpwReturnCode);

 
The first argument of this function is a pointer to the number of the HLLAPI function you want to call.  This parameter must be specified for every HLLAPI call.  The other three arguments vary depending on which function you are calling.  They will always be present but they have different meanings for different functions.  Please check the HLLAPI documentation (Winhlapi.hlp) in the samples directory for important details.
 
The prototypes for the Windows Extension calls are:

HANDLE WinHLLAPIAsync(hWnd, lpwFunction, lpbyString, lpwLength, lpwReturnCode);

BOOL WinHLLAPIIsBlocking(void);

int WinHLLAPICancelAsyncRequest(HANDLE hAsyncTaskID, WORD wFunction);

int WinHLLAPICancelBlockingCall(void);

FARPROC WinHLLAPISetBlockingHook(FARPROC lpBlockFunc);

BOOL WinHLLAPIUnhookBlockingHook(void);

BOOL WinHLLAPICleanup(void);

int WinHLLAPIStartup(WORD wVersionRequired, LPWHLLAPIDATA lpData);

Details of the actual Windows HLLAPI implementation are described in the WHLLAPIDATA structure defined as follows:

typedef struct tagWHLLAPIDATA

{

        WORD wVersion;

        char szDescription[WHLLDESCRIPTION_LEN + 1];

} WHLLAPIDATA, * PWHLLAPIDATA, FAR * LPWHLLAPIDATA;