WOW32DriverCallback

BOOL WOW32DriverCallback(dwCallback, dwFlags, wDeviceHandle, wMsg, dwUser,
    dwParam1, dwParam2)
DWORD  dwCallback;
DWORD  dwFlags;
WORD  wDeviceHandle;
WORD  wMsg;
DWORD  dwUser;
DWORD  dwParam1;
DWORD  dwParam2;

WOW32DriverCallback allows a 32-bit thunk extension DLL to simulate a Multimedia hardware interrupt callback into 16-bit code. The built-in thunks for wave, midi, and time callbacks make use of this function to callback into 16-bit application code.

Parameters

dwCallback

Specifies either the address of a callback function, a window handle, or a task handle, depending on the flags specified in dwFlags.

dwFlags

Specifies how the 16-bit client application is notified, according to one of the following flags:

Flag	Meaning
DCB_FUNCTION	Indicates that a message should be sent to a callback function. dwCallback must be a 16-bit address of the 16-bit application callback routine.
DCB_WINDOW	Indicates that a message should be sent to the 16-bit window handle specified in dwCallback.
DCB_TASK	Indicates that a message should be sent ot the 16-bit task handle specified in dwCallback.

wDeviceHandle

Specifies a 16-bit handle of the device associated with the notification.

wMsg

Specifies a message to be sent to the application.

dwUser

Specifies the DWORD of user-instance data supplied by the application when the device was opened.

dwParam1

Specifies a message-dependent parameter. If this is a pointer, it must be mapped to a valid 16-bit address. All fields in the structure pointed to must be mapped correctly.

dwParam2

Specifies a message-dependent parameter. If this is a pointer, it must be mapped to a valid 16-bit address. All fields in the structure pointed to must be mapped correctly.

Return Value

WOW32DriverCallback returns TRUE if the operation was successful.

Comments

The 16-bit client specifies how it is notified when the device is opened. If notification is accomplished with a callback function, wDeviceHandle, wMsg, dwUser, dwParam1, and dwParam2 are passed to the callback. If notification is accomplished by means of a window, only wMsg, wDeviceHandle, and dwParam1 are passed.

Users will have to dynamically link to this function.

See Also

WOW32ResolveHandle