Figure 2   Windows Explorer Shell Versions

Version	Platform	Interfaces Supported
4.0	Windows 95, Windows NT 4.0, Internet Explorer 3.0, and Internet Explorer 4.0 without Web Integrated Desktop	IShellFolder, IPersistFolder, IShellView, IEnumIDList, IExtractIcon, IContextMenu, IContextMenu2, IDataObject, IDropSource, and IdropTarget
4.71	Internet Explorer 4.0 with Web Integrated Desktop	Same as version 4.00 plus IShellView2 and IContextMenu3
4.72	Internet Explorer 4.01 with Integrated Desktop, Windows 98 beta 3, and Windows NT 5.0 beta 1	Same as version 4.71 plus IPersistFolder2

Figure 3   GetShellVersion

 #include <windows.h>
 #include <shlwapi.h>
 
 HRESULT GetShellVersion(LPDWORD pdwMajorVersion, LPDWORD pdwMinorVersion)
 {
     HINSTANCE   hShell32 = NULL;
 
     if( IsBadWritePtr(pdwMajor, sizeof(DWORD)) || 
         IsBadWritePtr(pdwMinor, sizeof(DWORD)))
         return E_INVALIDARG;
 
     *pdwMajor = 0;
     *pdwMinor = 0;
 
     //Load the DLL.
     hShell32 = ::LoadLibrary(TEXT("shell32.dll"));
 
     if ( NULL == hShell32 )
         return E_FAIL;
 
     HRESULT hr = S_OK;
     DLLGETVERSIONPROC pDllGetVersion = { 0 };
    
 
     //You must get this function explicitly because earlier versions of the DLL 
     //Do not implement this function.
 
     pDllGetVersion = (DLLGETVERSIONPROC)::GetProcAddress(hShell32,     
                                                          _T("DllGetVersion"));
    
     if (!pDllGetVersion )
     {
         ::FreeLibrary(hShell32);
         return E_FAIL;
     }
 
     DLLVERSIONINFO    DllVersionInfo;
       
     ZeroMemory(&DllVersionInfo, sizeof(DllVersionInfo));
     DllVersionInfo.cbSize = sizeof(DllVersionInfo);
    
     hr = (*pDllGetVersion)(&DllVersionInfo);
       
     if ( SUCCEEDED( hr ))
     {
         *pdwMajor = DllVersionInfo.dwMajorVersion;
         *pdwMinor = DllVersionInfo.dwMinorVersion;
     }
     else
     {
         // If the function does not exists, then the DLL is a version 
         // older than Internet Explorer 3.x
 
         *pdwMajor = 4;
         *pdwMinor = 0;
     }
    
     ::FreeLibrary(hShell32);
 
     return hr;
 }

Figure 5   STRRET Values

Value	Meaning
STRRET_WSTR	Use STRRET.pOleStr field by returning a unicode string allocated using the IMalloc object returned from SHGetMalloc
STRRET_OFFSET	Use STRRET.uOffset field to tell Windows Explorer how many bytes from the start if the PIDL to where the title can be found in the PIDL
STRRET_CSTR	Use STRRET.cStr to copy the ANSI string into this field

Figure 6   Object Attributes

GetAttributes Flag	Meaning
SFGAO_CANCOPY	Object can be copied
SFGAO_CANMOVE	Object can be moved
SFGAO_CANLINK	Object can be linked
SFGAO_CANRENAME	Object can be renamed
SFGAO_CANDELETE	Object can be deleted
SFGAO_HASPROPSHEET	Object has property sheets
SFGAO_DROPTARGET	Object is a drop target
SFGAO_LINK	the Object is a shortcut (link)
SFGAO_SHARE	the Object is shared
SFGAO_READONLY	the Object is read-only
SFGAO_GHOSTED	the Object should have a ghosted icon
SFGAO_HIDDEN	the Object is a hidden object
SFGAO_FOLDER	the Object is a folder
SFGAO_HASSUBFOLDER	the Object has children

 HRESULT CADSIExtractIconA::GetIconLocation(UINT /*uFlags*/,
                                            LPSTR szIconFile, UINT cchMax, 
                                            int * piIndex, UINT * pwFlags)
 {
     // get the module file name
     if ( 0 ==::GetModuleFileNameA(_Module.GetModuleInstance(),
                                   szIconFile,cchMax) )
     {
         DWORD dwError = ::GetLastError();
         return HRESULT_FROM_WIN32(dwError);
     }
 
     // if there document is a place for the Icon Index
     if ( NULL != piIndex )
     {
         // by turning on the high order bit flags the values is a resource ID
         *piIndex = -1 * (int)m_dwIcon;
     }
 
     // set that there are no special requirements on the icons
     if ( NULL != pwFlags )
     {
         *pwFlags = 0;
     }
     // return all is well
     return S_OK;
 }
 
 HRESULT CADSIExtractIconA::Extract(LPCSTR /*pszFile*/,UINT /*nIconIndex*/,
     HICON * /*phiconLarge*/,HICON * /*phiconSmall*/,UINT /*nIconSize*/)
 {
     // tell the calling app to load the icon itself
     return S_FALSE;
 }

State	Definition
SVUIA_DEACTIVATE	The view will be placed in this state when the Windows Explorer is about to destroy the shell view window. The shell view is required to remove the menus, toolbars, and any windows or UI objects that have been created.
SVUIA_ACTIVATE_NOFOCUS	The view will be placed in this state when the namespace extension's shell view has just created a window. The shell view has been created without focus and should set the menus accordingly.
SVUIA_ACTIVATE_FOCUS	The view will be placed in this state when Windows Explorer sets focus to the shell view window. The menus and view selections should reflect that the view has input focus.
SVUIA_INPLACEACTIVATE	The view will be placed in this state when the shell view is opened within an ActiveX control. The view is not in a UI active state. In this case, the shell view should not merge menus or install toolbars. To be compatible with the Windows 95 client, this value is not passed unless the view supports IShellView2.