CM_Enumerate_Classes function (cfgmgr32.h)

The CM_Enumerate_Classes function, when called repeatedly, enumerates the local machine's installed device classes by supplying each class's GUID.

Syntax

CMAPI CONFIGRET CM_Enumerate_Classes(
  [in]  ULONG  ulClassIndex,
  [out] LPGUID ClassGuid,
  [in]  ULONG  ulFlags
);

Parameters

[in] ulClassIndex

Caller-supplied index into the machine's list of device classes. For more information, see the Remarks section.

[out] ClassGuid

Caller-supplied address of a GUID structure (described in the Microsoft Windows SDK) to receive a device class's GUID.

[in] ulFlags

Beginning with Windows 8, callers can specify the following flags:

CM_ENUMERATE_CLASSES_INSTALLER

Enumerate device setup classes.

CM_ENUMERATE_CLASSES_INTERFACE

Enumerate device interface classes.

Otherwise, should be set to zero.

Return value

If the operation succeeds, the function returns CR_SUCCESS. Otherwise, it returns one of the CR_-prefixed error codes defined in Cfgmgr32.h.

Remarks

To enumerate the local machine's device classes, call CM_Enumerate_Classes repeatedly, starting with a ulClassIndex value of zero and incrementing the index value with each subsequent call until the function returns CR_NO_SUCH_VALUE. Some index values might represent list entries containing invalid class data, in which case the function returns CR_INVALID_DATA. This return value can be ignored.

The class GUIDs obtained from this function can be used as input to the device installation functions.

Beginning with Windows 8 and later operating systems, callers can use the ulFlags member to specify which device classes CM_Enumerate_Classes should return. Prior to Windows 8, CM_Enumerate_Classes returned only device setup classes.

Requirements

See also

CM_Enumerate_Classes_Ex