The DRV_FREE message requests a user-mode multimedia driver to perform pre-unload operations.
Parameters
dwDriverID
Driver instance identifier. This value is zero for the DRV_FREE message.
hDriver
Driver handle.
uMsg
DRV_FREE
lParam1
Not used. Set to zero.
lParam2
Not used. Set to zero.
Return Value
The driver should return a nonzero value if the operation succeeds. Otherwise it should return zero.
Comments
The DRV_FREE message is one of the standard driver messages. A client sends the message by calling the driver's DriverProc entry point, passing the specified parameter values.
User-mode drivers receive the DRV_FREE message just prior to being freed (unloaded) from memory. It is the last message a driver receives before being unloaded. The driver should release acquired system resources.
Drivers receive DRV_CLOSE and DRV_DISABLE messages before receiving DRV_FREE.