CM_NOTIFY_EVENT_DATA structure (cfgmgr32.h)

This is a device notification event data structure.

Syntax

typedef struct _CM_NOTIFY_EVENT_DATA {
  CM_NOTIFY_FILTER_TYPE FilterType;
  DWORD                 Reserved;
  union {
    struct {
      GUID  ClassGuid;
      WCHAR SymbolicLink[ANYSIZE_ARRAY];
    } DeviceInterface;
    struct {
      GUID  EventGuid;
      LONG  NameOffset;
      DWORD DataSize;
      BYTE  Data[ANYSIZE_ARRAY];
    } DeviceHandle;
    struct {
      WCHAR InstanceId[ANYSIZE_ARRAY];
    } DeviceInstance;
  } u;
} CM_NOTIFY_EVENT_DATA, *PCM_NOTIFY_EVENT_DATA;

Members

FilterType

The CM_NOTIFY_FILTER_TYPE from the CM_NOTIFY_FILTER structure that was used in the registration that generated this notification event data.

Reserved

Reserved. Must be 0.

u

A union that contains information about the notification event data. To determine which member of the union to examine, check the FilterType of the event data.

u.DeviceInterface

Examine this part of the union when the FilterType is CM_NOTIFY_FILTER_TYPE_DEVICEINTERFACE.

u.DeviceInterface.ClassGuid

The GUID of the device interface class for the device interface to which the notification event data pertains.

u.DeviceInterface.SymbolicLink[ANYSIZE_ARRAY]

The symbolic link path of the device interface to which the notification event data pertains.

u.DeviceHandle

Examine this part of the union when the FilterType is CM_NOTIFY_FILTER_TYPE_DEVICEHANDLE and the notification action is CM_NOTIFY_ACTION_DEVICECUSTOMEVENT.

u.DeviceHandle.EventGuid

The GUID for the custom event.

u.DeviceHandle.NameOffset

The offset of an optional string buffer. Usage depends on the contract for the EventGuid.

u.DeviceHandle.DataSize

The number of bytes that can be read from the Data member.

u.DeviceHandle.Data[ANYSIZE_ARRAY]

Optional binary data. Usage depends on the contract for the EventGuid.

u.DeviceInstance

Examine this part of the union when the FilterType is CM_NOTIFY_FILTER_TYPE_DEVICEINSTANCE.

u.DeviceInstance.InstanceId[ANYSIZE_ARRAY]

The device instance ID of the device to which the notification event data pertains.

Remarks

The notification callback supplied to CM_Register_Notification receives a pointer to a structure of type CM_NOTIFY_EVENT_DATA in the callback's EventData parameter.

Requirements

Requirement	Value
Header	cfgmgr32.h

See also

CM_Register_Notification