DrvNumberOfDevices

LONG
    DrvNumberOfDevices(
        PREG_ACCESS RegAccess,
        LPDWORD NumberOfDevices
        );

The DrvNumberOfDevices function determines the number of device subkeys existing under the driver’s \Parameters key in the registry.

Parameters

RegAccess

Pointer to a globally-defined structure of type REG_ACCESS.

NumberOfDevices

Address of a location to receive the number of devices.

Return Value

Returns ERROR_SUCCESS if the operation succeeds. Otherwise returns one of the error codes defined in winerror.h.

Comments

The structure pointed to by RegAccess must be a single, globally-defined REG_ACCESS structure that the driver uses with all calls to drvlib.lib functions requiring a RegAccess parameter.

Drivers create device subkeys by calling DrvCreateDeviceKey.

Drivers must call DrvCreateServicesNode before calling DrvNumberOfDevices.

For additional information, see Installing and Configuring your Driver, Using drvlib.lib.