SHAddToRecentDocs function (shlobj_core.h)
Notifies the system that an item has been accessed, for the purposes of tracking those items used most recently and most frequently. This function can also be used to clear all usage data.
Syntax
void SHAddToRecentDocs(
UINT uFlags,
[in, optional] LPCVOID pv
);
Parameters
uFlags
Type: UINT
A value from the SHARD enumeration that indicates the form of the information pointed to by the pv parameter.
[in, optional] pv
Type: LPCVOID
A pointer to data that identifies the item that has been accessed. The item can be specified in this parameter in one of the following forms:
- A null-terminated string that contains the path and file name of the item.
- A PIDL that identifies the item's file object.
- Windows 7 and later only. A SHARDAPPIDINFO, SHARDAPPIDINFOIDLIST, or SHARDAPPIDINFOLINK structure that identifies the item through an AppUserModelID. See Application User Model IDs (AppUserModelIDs) for more information.
- Windows 7 and later only. An IShellLink object that identifies the item through a shortcut.
Set this parameter to NULL to clear all usage data on all items.
Return value
None
Remarks
The usage statistics gathered through calls to this method are used to determine lists of items accessed most recently and most frequently. These lists are seen in the Start menu and, in Windows 7 and later, in an application's Jump List.
When this method is called, it affects the following areas:
- Updates the Recent and Frequent lists for the associated application's Jump List.
- Adds a shortcut to the user's Recent folder (FOLDERID_Recent, CSIDL_RECENT). This is reflected in the My Recent Documents (Windows XP) and Recent Items (Windows Vista and later) menu in the Start menu.
- Adds a shortcut to the Classic Start menu's Documents submenu. (Note that the Classic Start menu option is not available in Windows 7 and later.)
In some cases, notably when a user opens an item through Windows Explorer or uses the common file dialog to open, save, or create a file, the Shell calls SHAddToRecentDocs on behalf of the application. An application that has a custom UI for selecting items should call SHAddToRecentDocs explicitly to ensure accurate statistics. Duplicate calls are accounted for by the system so there is no risk of skewing the data by doing so.
Executable (.exe) files are filtered from the recently used documents list in Windows XP and later versions. Although SHAddToRecentDocs will accept the path of an executable file, that file will not appear in the Recent Items list.
Folders are also accepted by SHAddToRecentDocs, but appear only in the Jump List for the Windows Explorer taskbar button. Folders do not appear in any other application's Jump List.
In certain cases, SHAddToRecentDocs attempts to register an application to handle a file type that it is not registered to handle. This occurs under these circumstances:
- An application explicitly calls SHAddToRecentDocs with a file type that it is not registered to handle. This also applies to calls made to SHAddToRecentDocs by the common file dialog on behalf of the application, but only when the dialog is used to open a file, not when it is used to save one.
- The user drops a file of a type that the application is not registered to handle on the application's taskbar button.
A set of requirements must be met for the registration to be accomplished successfully:
- The application must be registered under HKEY_CLASSES_ROOT\Applications.
- That registration cannot include the NoOpenWith value. See File Types for more details on NoOpenWith.
- That registration cannot supply data under a SupportedTypes subkey. See File Types for more details on the SupportedTypes subkey.
-
The application's executable file cannot be listed in the KillList value found here:
HKEY_LOCAL_MACHINE Software Microsoft Windows CurrentVersion Explorer FileAssociation KillList
Note Third party applications should not modify the KillList value. It should be regarded as read-only. -
The application's HKEY_CLASSES_ROOT\Applications registration must have a set of default verbs defined under a
HKEY_CLASSES_ROOT\Applications\ExampleApp.exe\shell subkey.
If SHAddToRecentDocs is attempting the registration as the result of a drag-and-drop onto the taskbar button, the shell subkey is created if it does not already exist, as long as the existing application registration does not contain a NoOpenWith value and the application's executable is not listed in the KillList value.
Suppressing Calls to SHAddToRecentDocs
In versions of Windows before Windows 7, a file type could set the FTA_NoRecentDocs flag to prevent that file type from being added to the Recent folder. This mechanism is also supported under Windows 7 and later. See File Types for more information.SHAddToRecentDocs tracks document usage statistics through the verbs that are invoked to access those documents. Verbs supplied by registered IContextMenu handlers are tracked, those items appear in My Recent Documents (Windows XP) and Recent Items (Windows Vista). In Windows 7, the parent folders of the documents appear in the Jump List for the Windows Explorer taskbar button. However, the documents accessed through those IContextMenu verbs do not appear in application Jump Lists. For those items to appear in an application's Jump List, an application must call SHAddToRecentDocs explicitly.
Prior to Windows 7, only the open verb resulted in a call to SHAddToRecentDocs. In Windows 7 and later, other verbs can also generate usage statistics. This information is used to make a Jump List's destinations more complete and accurate.
However, some classes of file type association registrations or individual IContextMenu implementations are not appropriate for this sort of tracking. The point of usage tracking is to generate a list of items that the user is likely to want to access again. If a particular verb—delete, for instance—is inherently invoked on an item that the user will not access again, or is a secondary action such as a virus scan on a file, that verb is not appropriate for tracking. File type classes should remove themselves from this tracking through the registry entry NoRecentDocs. NoRecentDocs is of type REG_SZ and has no associated data. Its presence is all that is required to prevent the call to SHAddToRecentDocs.
For example, context menu extensions and static verbs registered under HKEY_CLASSES_ROOT in classes such as "*", "AllFileSystemObjects", or "Folder" should not be tracked. In cases such as these, the NoRecentDocs entry is added to the root of the class key as shown here to suppress tracking of documents launched through any verb or extension registered to that class:
HKEY_CLASSES_ROOT AllFileSystemObjects NoRecentDocs
The NoRecentDocs entry is assigned by default to the *, AllFileSystemObjects, Folder, Directory, and DesktopBackground class subkeys.
Individual IContextMenu implementations can opt out of tracking by adding a NoRecentDocs subkey to its Component Object Model (COM) object's registration, in its shellex subkey, as shown here:
HKEY_CLASSES_ROOT
CLSID
{093C7AAB-5E72-454f-A91D-CA1BC991FCEC}
shellex
NoRecentDocs
This subkey is not present by default on any IContextMenu implementation.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows XP [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | shlobj_core.h (include Shlobj.h) |
| Library | Shell32.lib |
| DLL | Shell32.dll (version 4.0 or later) |
| API set | ext-ms-win-shell-shell32-l1-2-2 (introduced in Windows 10, version 10.0.14393) |