MCI_OPEN_DRIVER

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

Opening an MCI Driver, MCI_CLOSE_DRIVER