Figure 7   Namespace Extension COM Interface Method

Method	Description	Step
IShellFolder
BindToObject	Retrieves the IShellFolder interface for the subfolder.	2
CreateViewObject	Creates a view object of the folder.	1
CompareIDs	Determines the relative order of two file objects or folders, given their item identifier lists.	2
EnumObjects	Enumerates the objects in a folder.	2
GetAttributesOf	Retrieves the attributes of the specified file object or subfolder.	1
GetDisplayNameOf	Retrieves the display name of a file object or subfolder.	2
GetUIObjectOf	Creates an OLE interface that can be used to carry out operations on a file object or subfolder like a context menu, icon extraction, data object for copying data, and so on.	4
ParseDisplayName	Translates a display name into an item identifier list.
SetNameOf	Sets the display name of the specified file object or subfolder and changes its identifier accordingly.
BindToStorage	Reserved for future use.
IShellView
CreateViewWindow	Creates the view window.	1
DestroyViewWindow	Destroys the view window.	1
GetCurrentInfo	Returns the current folder settings.
GetItemObject	Allows callers to get an object that represents something in the view.
Refresh	Refreshes the display in response to user input.
SaveViewState	Saves the shell's view settings so the current state can be restored during a subsequent browsing session.
SelectItem	Changes the state of items within the shell view window.
TranslateAccelerator	Translates accelerator key strokes when a namespace extension's view has the focus.
UIActivate	Called whenever the activation state of the view window is changed by an event not caused by the shell view itself.	3
AddPropertySheetPages	Allows the view to add pages to the Options property sheet.
EnableModeless	Enables or disables modeless dialog boxes. Not in use by Windows Explorer at this time.
EnableModelessSV	Reserved for future use.
IEnumIDList
Clone	Creates a new item enumeration object identical to the current one.	2
Next	Retrieves the specified number of item identifiers.	2
Reset	Returns to the beginning of the enumeration.	2
Skip	Skips over the specified number of items.	2

Figure 8   SHITEMID and IDLIST

 //
 // SHITEMID -- Item ID
 //
 typedef struct _SHITEMID // mkid
 {
 USHORT cb; // Size of the ID (including cb itself)
 BYTE abID[1]; // The item ID (variable length)
 } SHITEMID;
 typedef UNALIGNED SHITEMID *LPSHITEMID;
 typedef const UNALIGNED SHITEMID *LPCSHITEMID;
 
 //
 // ITEMIDLIST -- List if item IDs (combined with 0-terminator)
 //
 typedef struct _ITEMIDLIST // idl
 {
 SHITEMID mkid;
 } ITEMIDLIST;
 typedef UNALIGNED ITEMIDLIST * LPITEMIDLIST;
 typedef const UNALIGNED ITEMIDLIST * LPCITEMIDLIST;

Figure 9   IDL Data Structures

 // From EnumIDL.h
 typedef enum tagMYPIDLTYPE
 {
     PT_ROOT    = 0x00,
     PT_FOLDER  = 0x01,
     PT_FILE    = 0x02,
     PT_INVALID = 0x04
 }MYPIDLTYPE;
 
 typedef struct tagMYPIDLDATA
 {
     char        szSignature[4];    
     MYPIDLTYPE  pidlType;
     DWORD       dwSizeHigh;
     DWORD       dwSizeLow;
     DWORD       dwAttribs;
     FILETIME    ftLastWriteTime;
     UINT        uiSizeFile;
     UINT        uiSizeType;
     // uiSizeFile, uiSizeType contain the size of 
     // File & Type strings from szFileAndType
     TCHAR       szFileAndType[1];
 }MYPIDLDATA, FAR *LPMYPIDLDATA;

Figure 10   IShell Browser Methods

Method	Description	Step
BrowseObject	Tells Windows Explorer to browse in another folder.
EnableModelessSB	Enables or disables modeless windows of Windows Explorer, such as a floating toolbar.
GetControlWindow	Gets the window handle to a Windows Explorer control.
GetViewStateStream	Returns a view-specific stream that can be used to read and write the persistent data for a view.
InsertMenusSB	Inserts the Windows Explorer menu items in an empty menu created by the view.	3
OnViewWindowActive	Informs Windows Explorer that the view was activated.
QueryActiveShellView	Returns the currently activated (displayed) shell view object.
RemoveMenusSB	Instructs the container to remove its items from a composite menu. The tasks it performs are the opposite of InsertMenuSB tasks.	3
SendControlMsg	Sends messages to Windows Explorer controls.	3
SetMenuSB	Installs the composite menu in Windows Explorer.	3
SetStatusTextSB	Sets and displays status text in the Windows Explorer window.	3
SetToolbarItems	Adds toolbar items to the Windows Explorer toolbar.	3
TranslateAcceleratorSB	Reserved for future use.

Figure 11   IContext Menu and IExtract Icon

Method	Description	Step
IContextMenu
GetCommandString	Retrieves the help text for a menu command or the language-independent name of a menu command.	4
InvokeCommand	Carries out a menu command.	4
QueryContextMenu	Adds menu items to the specified menu.	4
IExtractIcon
Extract	Extracts an icon from the specified location.
GetIconLocation	Retrieves the icon location for an object.

Figure 12   More Namespace Extension Methods

Method	Description	Step
IDataObject
GetData	Renders the data described in a FORMATETC structure and transfers it through the STGMEDIUM structure.	5
GetDataHere	Renders the data described in a FORMATETC structure and transfers it through the STGMEDIUM structure allocated by the caller.
QueryGetData	Determines whether the data object is capable of rendering the data described in the FORMATETC structure.	5
GetCanonicalFormatEtc	Provides a potentially different but logically equivalent FORMATETC structure.
SetData	Provides the source data object with data described by a FORMATETC structure and an STGMEDIUM structure.	5
EnumFormatEtc	Creates and returns a pointer to an object to enumerate the FORMATETC supported by the data object.
DAdvise	Creates a connection between a data object and an advise sink so the advise sink can receive notifications of changes in the data object.
DUnadvise	Destroys a notification previously set up with the DAdvise method.
EnumDAdvise	Creates and returns a pointer to an object to enumerate the current advisory connections.
IDropSource
QueryContinueDrag	Determines whether a drag-and-drop operation should continue.
GiveFeedback	Gives visual feedback to an end user during a drag-and-drop operation.
IDropTarget
DragEnter	Determines whether a drop can be accepted and its effect if it is accepted.
DragOver	Provides target feedback to the user through the DoDragDrop function.
DragLeave	Causes the drop target to suspend its feedback actions.
Drop	Drops the data into the target window.
IEnumFORMATETC
Next	Retrieves a specified number of items in the enumeration sequence.
Skip	Skips over a specified number of items in the enumeration sequence.
Reset	Resets the enumeration sequence to the beginning.
Clone	Creates another enumerator that contains the same enumeration state as the current one.