Extensibility

File Explorer can be continued to abutment non-default functionality by agency of Windows Carapace Extensions, which are COM altar that bung the continued functionality into Windows Explorer.22 Carapace extensions can be in the anatomy of carapace addendum handlers, toolbars or even namespace extensions that acquiesce assertive folders (or even non-filesystem altar such as the images scanned by a scanner) to be presented as a adapted folder. Book Explorer aswell allows metadata for files to be added as NTFS Alternate Abstracts Streams, abstracted from the abstracts beck for the file.

Shell addendum handlers are queried by the carapace advanced for modifying the activity the carapace takes. They can be associated on a per-file blazon base - area they will appearance up alone if a accurate activity takes abode on a accurate book blazon - or on a all-around base - which are consistently available. The carapace supports the afterward addendum handlers:

Handler Description Can be implemented on Required carapace version

Context card handler Adds card items to the ambience menu. It is alleged afore the ambience card is displayed. Per-file blazon basis Windows 95 and later. Windows 7 alien IExecuteCommand

Drag-and-drop handler Controls the activity aloft right-click annoyance and bead and modifies the ambience card that appears. Global basis Windows 95 and later

Drop ambition handler Controls the activity afterwards a abstracts article is abject and alone over a bead ambition such as a file. Per-file blazon basis Windows 95 and later

Data article handler Controls the activity afterwards a book is affected to the clipboard or abject and alone over a bead target. It can accommodate added clipboard formats to the bead target. Per-file blazon basis Windows 95 and later

Icon handler Assigns a custom figure to an alone book amidst a chic of book types. It is alleged afore book icons are displayed. Per-file blazon basis Windows 95 and later

Property area handler Replaces or adds pages to the acreage area chat box of an object. Per-file blazon basis Windows 95 and later

Copy angle handler Allows running, modifying or abstinent the activity if a user or appliance tries to copy, move, delete, or rename an object. Not associated with a book type Windows 95 and later

Search handler Allows carapace affiliation of a custom seek engine. Not associated with a book type Windows 95 and afterwards up to Windows XP

Infotip handler Allows retrieving flags and infotip advice for an account and announcement it central a popup tooltip aloft abrasion hover. Per-file blazon basis Windows Desktop Update and later

Thumbnail angel handler Provides for a thumbnail angel to be generated and displayed forth with its alpha blazon if a book is called or the thumbnail appearance is activated. Per-file blazon basis Windows Desktop Update and later. Windows Vista alien a newer IThumbnailProvider interface that aswell shows thumbnails in the Abstracts pane. The earlier IExtractImage is still accurate but not in the Abstracts pane.23

Disk Cleanup handler Add a new access to the Deejay Cleanup appliance and allows allegorical added deejay locations or files to apple-pie up. Per-folder basis Windows 98 and later

Column handler Allows creating and announcement custom columns in Windows Explorer Abstracts view. It can be acclimated to extend allocation and grouping. Per-folder basis Windows 2000, Windows Me, Windows XP & Server 2003

Icon bury handler Allows announcement an bury figure over a carapace article (a book or binder icon). Per-file blazon basis Windows 2000 and later

Metadata handler Allows examination and modifying metadata stored in a file. It can be acclimated to extend abstracts appearance columns, infotips, acreage pages, allocation and grouping. Per-file blazon basis Windows 2000 and later

Filter abettor (IFilter) Allows book backdrop and its capacity to be indexed and searched by Indexing Service or Windows Search Per-file blazon basis Windows 2000 and later

AutoPlay handler Examines anew apparent disposable media and accessories and, based on agreeable such as pictures, music or video files, launches an adapted appliance to play or affectation the content. Per book blazon category. In Windows XP only, per-device and per book blazon category. Windows XP and later

Property handler Allows examination and modifying system-defined and custom backdrop of a file. Per-file blazon basis Windows Vista and later, on Windows XP if Windows Seek is installed.

Preview handler Renders added previews of items after ablution the absence appliance if a book is selected. It can aswell accommodate book type-specific aeronautics such as browsing a document, or gluttonous central a media file. Per-file blazon basis Windows Vista and later

Namespace extensions are acclimated by Explorer to either affectation some abstracts - which are not persisted as files - in a folder-like appearance or to present abstracts in a way that is altered from their alignment on the book system. This affection can be exploited by a Relational Book Arrangement like liquidFOLDERS or Tabbles, clones of the blighted Microsoft WinFS. Adapted Folders, such as My Computer and Network Places in Windows Explorer are implemented this way, as are Explorer angle that let items in a adaptable buzz or agenda camera be explored. Source-control systems that use Explorer to browse antecedent repositories aswell use Namespace extensions to acquiesce Explorer to browse the revisions. To apparatus a namespace extension, the IPersistFolder, IShellView, IShellFolder, IShellBrowser and IOleWindow interfaces needs to be implemented and registered. The accomplishing needs to accommodate the argumentation for abyssal the abstracts abundance as able-bodied as anecdotic the presentation. Windows Explorer will instantiate the COM altar as required.24

While Windows Explorer natively exposes the adaptability credibility as COM interfaces, .NET Framework can aswell be acclimated to address extensions, application the COM Interop functionality of .NET Framework.24 While Microsoft itself makes accessible extensions - such as the Photo Info tool25 - which are authored application .NET Framework, they currently acclaim adjoin autograph managed carapace extensions, as alone one instance of the CLR (prior to adaptation 4.0) can be loaded per-process. This behavior would could cause conflicts if assorted managed add-ins, targeting altered versions of the CLR, are attempted to be run simultaneously.2627