SHChangeNotify function (shlobj_core.h)

Notifies the system of an event that an application has performed. An application should use this function if it performs an action that may affect the Shell.

Syntax

void SHChangeNotify(
                 LONG    wEventId,
                 UINT    uFlags,
  [in, optional] LPCVOID dwItem1,
  [in, optional] LPCVOID dwItem2
);

Parameters

wEventId

Type: LONG

Describes the event that has occurred. Typically, only one event is specified at a time. If more than one event is specified, the values contained in the dwItem1 and dwItem2 parameters must be the same, respectively, for all specified events. This parameter can be one or more of the following values:

SHCNE_ALLEVENTS

All events have occurred.

SHCNE_ASSOCCHANGED

A file type association has changed. SHCNF_IDLIST must be specified in the uFlags parameter. dwItem1 and dwItem2 are not used and must be NULL. This event should also be sent for registered protocols.

SHCNE_ATTRIBUTES

The attributes of an item or folder have changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item or folder that has changed. dwItem2 is not used and should be NULL.

SHCNE_CREATE

A nonfolder item has been created. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item that was created. dwItem2 is not used and should be NULL.

SHCNE_DELETE

A nonfolder item has been deleted. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item that was deleted. dwItem2 is not used and should be NULL.

SHCNE_DRIVEADD

A drive has been added. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that was added. dwItem2 is not used and should be NULL.

SHCNE_DRIVEADDGUI

Windows XP and later: Not used.

SHCNE_DRIVEREMOVED

A drive has been removed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that was removed. dwItem2 is not used and should be NULL.

SHCNE_EXTENDED_EVENT

Not currently used.

SHCNE_FREESPACE

The amount of free space on a drive has changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive on which the free space changed. dwItem2 is not used and should be NULL.

SHCNE_MEDIAINSERTED

Storage media has been inserted into a drive. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive that contains the new media. dwItem2 is not used and should be NULL.

SHCNE_MEDIAREMOVED

Storage media has been removed from a drive. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the root of the drive from which the media was removed. dwItem2 is not used and should be NULL.

SHCNE_MKDIR

A folder has been created. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that was created. dwItem2 is not used and should be NULL.

SHCNE_NETSHARE

A folder on the local computer is being shared via the network. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that is being shared. dwItem2 is not used and should be NULL.

SHCNE_NETUNSHARE

A folder on the local computer is no longer being shared via the network. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that is no longer being shared. dwItem2 is not used and should be NULL.

SHCNE_RENAMEFOLDER

The name of a folder has changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the previous PIDL or name of the folder. dwItem2 contains the new PIDL or name of the folder.

SHCNE_RENAMEITEM

The name of a nonfolder item has changed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the previous PIDL or name of the item. dwItem2 contains the new PIDL or name of the item.

SHCNE_RMDIR

A folder has been removed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that was removed. dwItem2 is not used and should be NULL.

SHCNE_SERVERDISCONNECT

The computer has disconnected from a server. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the server from which the computer was disconnected. dwItem2 is not used and should be NULL.

SHCNE_UPDATEDIR

The contents of an existing folder have changed, but the folder still exists and has not been renamed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the folder that has changed. dwItem2 is not used and should be NULL. If a folder has been created, deleted, or renamed, use SHCNE_MKDIR, SHCNE_RMDIR, or SHCNE_RENAMEFOLDER, respectively.

SHCNE_UPDATEIMAGE

An image in the system image list has changed. SHCNF_DWORD must be specified in uFlags.

dwItem2 contains the index in the system image list that has changed. dwItem1 is not used and should be NULL.

SHCNE_UPDATEITEM

An existing item (a folder or a nonfolder) has changed, but the item still exists and has not been renamed. SHCNF_IDLIST or SHCNF_PATH must be specified in uFlags. dwItem1 contains the item that has changed. dwItem2 is not used and should be NULL. If a nonfolder item has been created, deleted, or renamed, use SHCNE_CREATE, SHCNE_DELETE, or SHCNE_RENAMEITEM, respectively, instead.

SHCNE_DISKEVENTS

Specifies a combination of all of the disk event identifiers.

SHCNE_GLOBALEVENTS

Specifies a combination of all of the global event identifiers.

SHCNE_INTERRUPT

The specified event occurred as a result of a system interrupt. As this value modifies other event values, it cannot be used alone.

uFlags

Type: UINT

Flags that, when combined bitwise with SHCNF_TYPE, indicate the meaning of the dwItem1 and dwItem2 parameters. The uFlags parameter must be one of the following values.

SHCNF_DWORD

The dwItem1 and dwItem2 parameters are DWORD values.

SHCNF_IDLIST

dwItem1 and dwItem2 are the addresses of ITEMIDLIST structures that represent the item(s) affected by the change. Each ITEMIDLIST must be relative to the desktop folder.

SHCNF_PATH

dwItem1 and dwItem2 are the addresses of null-terminated strings of maximum length MAX_PATH that contain the full path names of the items affected by the change.

SHCNF_PRINTER

dwItem1 and dwItem2 are the addresses of null-terminated strings that represent the friendly names of the printer(s) affected by the change.

SHCNF_FLUSH

The function should not return until the notification has been delivered to all affected components. As this flag modifies other data-type flags, it cannot be used by itself.

SHCNF_FLUSHNOWAIT

The function should begin delivering notifications to all affected components but should return as soon as the notification process has begun. As this flag modifies other data-type flags, it cannot by used by itself. This flag includes SHCNF_FLUSH.

SHCNF_NOTIFYRECURSIVE

Notify clients registered for all children.

[in, optional] dwItem1

Type: LPCVOID

Optional. First event-dependent value.

[in, optional] dwItem2

Type: LPCVOID

Optional. Second event-dependent value.

Return value

None

Remarks

Applications that register new handlers of any type must call SHChangeNotify with the SHCNE_ASSOCCHANGED flag to instruct the Shell to invalidate the icon and thumbnail cache. This will also load new icon and thumbnail handlers that have been registered. Note, however, that icon overlay handlers are not reloaded.

The strings pointed to by dwItem1 and dwItem2 can be either ANSI or Unicode.

Requirements