CM_NOTIFY_FILTER structure (cfgmgr32.h)

Article
10/17/2023

Device notification filter structure

Syntax

typedef struct _CM_NOTIFY_FILTER {
  DWORD                 cbSize;
  DWORD                 Flags;
  CM_NOTIFY_FILTER_TYPE FilterType;
  DWORD                 Reserved;
  union {
    struct {
      GUID ClassGuid;
    } DeviceInterface;
    struct {
      HANDLE hTarget;
    } DeviceHandle;
    struct {
      WCHAR InstanceId[MAX_DEVICE_ID_LEN];
    } DeviceInstance;
  } u;
} CM_NOTIFY_FILTER, *PCM_NOTIFY_FILTER;

Members

cbSize

The size of the structure.

Flags

A combination of zero or more of the following flags:

CM_NOTIFY_FILTER_FLAG_ALL_INTERFACE_CLASSES

Register to receive notifications for PnP events for all device interface classes. The memory at pFilter->u.DeviceInterface.ClassGuid must be zeroes. Do not use this flag with CM_NOTIFY_FILTER_FLAG_ALL_DEVICE_INSTANCES. This flag is only valid if pFilter->FilterType is CM_NOTIFY_FILTER_TYPE_DEVICEINTERFACE.

CM_NOTIFY_FILTER_FLAG_ALL_DEVICE_INSTANCES

Register to receive notifications for PnP events for all devices. pFilter->u.DeviceInstance.InstanceId must be an empty string. Do not use this flag with CM_NOTIFY_FILTER_FLAG_ALL_INTERFACE_CLASSES. This flag is only valid if pFilter->FilterType is CM_NOTIFY_FILTER_TYPE_DEVICEINSTANCE.

FilterType

Must be one of the following values:

CM_NOTIFY_FILTER_TYPE_DEVICEINTERFACE

Register for notifications for device interface events. pFilter->u.DeviceInterface.ClassGuid should be filled in with the GUID of the device interface class to receive notifications for.

CM_NOTIFY_FILTER_TYPE_DEVICEHANDLE

Register for notifications for device handle events. pFilter->u.DeviceHandle.hTarget must be filled in with a handle to the device to receive notifications for. This handle must remain a valid handle to the device for the duration of the CM_Register_Notification call. However, after CM_Register_Notification returns, the handle can be closed without affecting the ability for the registration to receive notifications.

CM_NOTIFY_FILTER_TYPE_DEVICEINSTANCE

Register for notifications for device instance events. pFilter->u.DeviceInstance.InstanceId should be filled in with the device instance ID of the device to receive notifications for.

Reserved

Set to 0.

u

A union that contains information about the device to receive notifications for.

u.DeviceInterface

u.DeviceInterface.ClassGuid

The GUID of the device interface class for which to receive notifications.

u.DeviceHandle

A handle to the device for which to receive notifications.

u.DeviceHandle.hTarget

u.DeviceInstance

The device instance ID for the device for which to receive notifications.

u.DeviceInstance.InstanceId[MAX_DEVICE_ID_LEN]

Remarks

When the driver calls the CM_Register_Notification function, it supplies a pointer to a CM_NOTIFY_FILTER structure in the pFilter parameter.

Requirements

Requirement	Value
Header	cfgmgr32.h

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