The MXDM_GETNUMDEVS message requests a user-mode mixer driver to return the number of device instances it supports.
Parameters
uDeviceId
Device identifier (0, 1, 2, and so on) for the target device.
uMsg
MXDM_GETNUMDEVS
dwUser
Not used.
lParam1
Not used.
lParam2
Not used.
Return Value
Returns the number of devices the driver supports.
Comments
A client sends the MXDM_GETNUMDEVS message by calling the user-mode driver’s mxdMessage entry point, passing the specified parameters.