The MCI_OPEN_DRIVER message requests an MCI driver to open a driver instance.
Parameters
dwDriverID
Driver instance identifier. This is the value returned by the driver in response to the DRV_OPEN message.
hDriver
Driver handle.
uMsg
MCI_OPEN_DRIVER
lParam1
Contains the flags specified by the application, with the MCI_OPEN command.
lParam2
Specifies a pointer to an MCI_OPEN_PARMS structure, or to a customized structure.
Return Value
If the operation succeeds, the driver returns zero. Otherwise, the driver returns one of the MCIERR error codes defined in mmsystem.h.
Comments
A client sends the message by calling the driver’s DriverProc entry point, passing the specified parameters. When an application sends an MCI_OPEN message, winmm.dll intercepts it and sends MCI_OPEN_DRIVER to the driver.
See Also