static public IList<IVsProject> GetProjectsOfCurrentSelections()
        {
            List<IVsProject> results = new List<IVsProject>();

            int hr = VSConstants.S_OK;
            var selectionMonitor = _serviceProvider.GetService(typeof(SVsShellMonitorSelection)) as IVsMonitorSelection;
            if (selectionMonitor == null)
            {
                Debug.Fail("Failed to get SVsShellMonitorSelection service.");
                return results;
            }

            IntPtr hierarchyPtr = IntPtr.Zero;
            uint itemID = 0;
            IVsMultiItemSelect multiSelect = null;
            IntPtr containerPtr = IntPtr.Zero;
            hr = selectionMonitor.GetCurrentSelection(out hierarchyPtr, out itemID, out multiSelect, out containerPtr);
            if (IntPtr.Zero != containerPtr)
            {
                Marshal.Release(containerPtr);
                containerPtr = IntPtr.Zero;
            }
            Debug.Assert(hr == VSConstants.S_OK, "GetCurrentSelection failed.");

            if (itemID == (uint)VSConstants.VSITEMID.Selection)
            {
                uint itemCount = 0;
                int fSingleHierarchy = 0;
                hr = multiSelect.GetSelectionInfo(out itemCount, out fSingleHierarchy);
                Debug.Assert(hr == VSConstants.S_OK, "GetSelectionInfo failed.");

                VSITEMSELECTION[] items = new VSITEMSELECTION[itemCount];
                hr = multiSelect.GetSelectedItems(0, itemCount, items);
                Debug.Assert(hr == VSConstants.S_OK, "GetSelectedItems failed.");

                foreach (VSITEMSELECTION item in items)
                {
                    IVsProject project = GetProjectOfItem(item.pHier, item.itemid);
                    if (!results.Contains(project))
                    {
                        results.Add(project);
                    }
                }
            }
            else
            {
                // case where no visible project is open (single file)
                if (hierarchyPtr != IntPtr.Zero)
                {
                    IVsHierarchy hierarchy = (IVsHierarchy)Marshal.GetUniqueObjectForIUnknown(hierarchyPtr);
                    results.Add(GetProjectOfItem(hierarchy, itemID));
                }
            }

            return results;
        }

        public SourceImage(VSITEMSELECTION item)
        {
            this.item = item;
            this.features = new ObservableCollection<OutputFeature>();

            InitSourcePathAndScale();
            InitSourceImage();

            OutputHelpers.PopulateFeatures(this);
            this.PostInitialize();
        }

      public Project[] GetSelectedProjects()
      {
         IntPtr hierarchyPointer, selectionContainerPointer;
         IVsMultiItemSelect multiItemSelect;
         uint projectItemId;

         MonitorSelectionService.GetCurrentSelection(out hierarchyPointer, out projectItemId, out multiItemSelect, out selectionContainerPointer);

         if (projectItemId == (uint)VSConstants.VSITEMID.Selection)
         {
            // Multiple projects are selected
            uint numberOfSelectedItems;
            int isSingleHieracrchy;
            multiItemSelect.GetSelectionInfo(out numberOfSelectedItems, out isSingleHieracrchy);

            var selectedItems = new VSITEMSELECTION[numberOfSelectedItems];

            multiItemSelect.GetSelectedItems(0, numberOfSelectedItems, selectedItems);

            var result = new Project[numberOfSelectedItems];
            for (int i = 0; i < numberOfSelectedItems; i++)
            {
               object selectedObject = null;
               ErrorHandler.ThrowOnFailure(selectedItems[i].pHier.GetProperty(selectedItems[i].itemid, (int)__VSHPROPID.VSHPROPID_ExtObject, out selectedObject));

               result[i] = selectedObject as Project;
            }
            return result;
         }
         else
         {
            // Only one project is selected
            object selectedObject = null;
            IVsHierarchy selectedHierarchy = null;
            try
            {
               selectedHierarchy = Marshal.GetTypedObjectForIUnknown(hierarchyPointer, typeof(IVsHierarchy)) as IVsHierarchy;
            }
            catch (Exception)
            {
               return null;
            }

            if (selectedHierarchy != null)
            {
               ErrorHandler.ThrowOnFailure(selectedHierarchy.GetProperty(projectItemId, (int)__VSHPROPID.VSHPROPID_ExtObject, out selectedObject));
            }

            Project selectedProject = selectedObject as Project;

            return new Project[] { selectedProject };
         }
      }

		public IEnumerable<IVsHierarchyItem> GetSelection ()
		{
			return asyncManager.Run (async () => {
				await asyncManager.SwitchToMainThread ();

				var selHier = IntPtr.Zero;
				uint selId;
				IVsMultiItemSelect selMulti;

				try {
					ErrorHandler.ThrowOnFailure (hierarchyWindow.GetCurrentSelection (out selHier, out selId, out selMulti));

					// There may be no selection at all.
					if (selMulti == null && selHier == IntPtr.Zero)
						return Enumerable.Empty<IVsHierarchyItem> ();

					// This is a single item selection.
					if (selMulti == null) {
						return new[] { hierarchyManager.GetHierarchyItem (
							(IVsHierarchy)Marshal.GetTypedObjectForIUnknown (selHier, typeof (IVsHierarchy)), selId) };
					}

					// This is a multiple item selection.

					uint selCount;
					int singleHier;
					ErrorHandler.ThrowOnFailure (selMulti.GetSelectionInfo (out selCount, out singleHier));

					var selection = new VSITEMSELECTION[selCount];
					ErrorHandler.ThrowOnFailure (selMulti.GetSelectedItems (0, selCount, selection));

					return selection.Where (sel => sel.pHier != null)
						.Select (sel => hierarchyManager.GetHierarchyItem (sel.pHier, sel.itemid))
						.ToArray ();

				} finally {
					if (selHier != IntPtr.Zero)
						Marshal.Release (selHier);
				}
			});
		}

        DataObject PackageSelectionDataObject(bool cutHighlightItems){
            CleanupSelectionDataObject(false, false, false);
            IVsUIHierarchyWindow w = this.projectMgr.GetIVsUIHierarchyWindow(VsConstants.Guid_SolutionExplorer);
            IVsSolution solution = this.GetService(typeof(IVsSolution)) as IVsSolution;
            IVsMonitorSelection ms = this.GetService(typeof(IVsMonitorSelection)) as IVsMonitorSelection;
            IntPtr psel;
            IVsMultiItemSelect itemSelect;
            IntPtr psc;
            uint vsitemid;
            StringBuilder sb = new StringBuilder();
            ms.GetCurrentSelection(out psel, out vsitemid, out itemSelect, out psc);

            IVsHierarchy sel = (IVsHierarchy)Marshal.GetTypedObjectForIUnknown(psel, typeof(IVsHierarchy));
            ISelectionContainer sc = (ISelectionContainer)Marshal.GetTypedObjectForIUnknown(psc, typeof(ISelectionContainer));

            const uint GSI_fOmitHierPtrs = 0x00000001;

            if ((sel != (IVsHierarchy)this) || (vsitemid == VsConstants.VSITEMID_ROOT) || (vsitemid == VsConstants.VSITEMID_NIL))
                throw new InvalidOperationException();

            if ((vsitemid == VsConstants.VSITEMID_SELECTION) && (itemSelect != null)){
                int singleHierarchy;
                uint pcItems;
                itemSelect.GetSelectionInfo(out pcItems, out singleHierarchy);
                if (singleHierarchy != 0) // "!BOOL" == "!= 0" ?
                    throw new InvalidOperationException();

                this.itemsDragged = new ArrayList();
                VSITEMSELECTION[] items = new VSITEMSELECTION[pcItems];
                itemSelect.GetSelectedItems(GSI_fOmitHierPtrs, pcItems, items);
                for (uint i = 0; i < pcItems; i++){
                    if (items[i].itemid == VsConstants.VSITEMID_ROOT){
                        this.itemsDragged.Clear();// abort
                        break;
                    }
                    this.itemsDragged.Add(items[i].pHier);
                    string projref;
                    solution.GetProjrefOfItem((IVsHierarchy)this, items[i].itemid, out projref);
                    if ((projref == null) || (projref.Length == 0)){
                        this.itemsDragged.Clear(); // abort
                        break;
                    }
                    sb.Append(projref);
                    sb.Append('\0'); // separated by nulls.
                }
            } else if (vsitemid != VsConstants.VSITEMID_ROOT){
                this.itemsDragged = new ArrayList();
                this.itemsDragged.Add(this.projectMgr.NodeFromItemId(vsitemid));

                string projref;
                solution.GetProjrefOfItem((IVsHierarchy)this, vsitemid, out projref);
                sb.Append(projref);
            }
            if (sb.ToString() == "" || this.itemsDragged.Count == 0)
                return null;

            sb.Append('\0'); // double null at end.

            _DROPFILES df = new _DROPFILES();
            int dwSize = Marshal.SizeOf(df);
            Int16 wideChar = 0;
            int dwChar = Marshal.SizeOf(wideChar);
            IntPtr ptr = Marshal.AllocHGlobal(dwSize + ((sb.Length + 1) * dwChar));
            df.pFiles = dwSize;
            df.fWide = 1;
            IntPtr data = DataObject.GlobalLock(ptr);
            Marshal.StructureToPtr(df, data, false);
            IntPtr strData = new IntPtr((long)data + dwSize);
            DataObject.CopyStringToHGlobal(sb.ToString(), strData);
            DataObject.GlobalUnLock(data);

            DataObject dobj = new DataObject();

            FORMATETC fmt = DragDropHelper.CreateFormatEtc();

            dobj.SetData(fmt, ptr);
            if (cutHighlightItems){
                bool first = true;
                foreach (HierarchyNode node in this.itemsDragged){
                    w.ExpandItem((IVsUIHierarchy)this.projectMgr, node.hierarchyId, first ? EXPANDFLAGS.EXPF_CutHighlightItem : EXPANDFLAGS.EXPF_AddCutHighlightItem);
                    first = false;
                }
            }
            return dobj;
        }

        /// <summary>
        /// Gets all of the currently selected items.
        /// </summary>
        /// <returns></returns>
        private IEnumerable<VSITEMSELECTION> GetSelectedItems() {
            IVsMonitorSelection monitorSelection = _package.GetService(typeof(IVsMonitorSelection)) as IVsMonitorSelection;

            IntPtr hierarchyPtr = IntPtr.Zero;
            IntPtr selectionContainer = IntPtr.Zero;
            try {
                uint selectionItemId;
                IVsMultiItemSelect multiItemSelect = null;
                ErrorHandler.ThrowOnFailure(monitorSelection.GetCurrentSelection(out hierarchyPtr, out selectionItemId, out multiItemSelect, out selectionContainer));

                if (selectionItemId != VSConstants.VSITEMID_NIL && hierarchyPtr != IntPtr.Zero) {
                    IVsHierarchy hierarchy = Marshal.GetObjectForIUnknown(hierarchyPtr) as IVsHierarchy;

                    if (selectionItemId != VSConstants.VSITEMID_SELECTION) {
                        // This is a single selection. Compare hirarchy with our hierarchy and get node from itemid
                        if (Utilities.IsSameComObject(this, hierarchy)) {
                            yield return new VSITEMSELECTION() { itemid = selectionItemId, pHier = hierarchy };
                        }
                    } else if (multiItemSelect != null) {
                        // This is a multiple item selection.
                        // Get number of items selected and also determine if the items are located in more than one hierarchy

                        uint numberOfSelectedItems;
                        int isSingleHierarchyInt;
                        ErrorHandler.ThrowOnFailure(multiItemSelect.GetSelectionInfo(out numberOfSelectedItems, out isSingleHierarchyInt));
                        bool isSingleHierarchy = (isSingleHierarchyInt != 0);

                        // Now loop all selected items and add to the list only those that are selected within this hierarchy
                        if (!isSingleHierarchy || (isSingleHierarchy && Utilities.IsSameComObject(this, hierarchy))) {
                            Debug.Assert(numberOfSelectedItems > 0, "Bad number of selected itemd");
                            VSITEMSELECTION[] vsItemSelections = new VSITEMSELECTION[numberOfSelectedItems];
                            uint flags = (isSingleHierarchy) ? (uint)__VSGSIFLAGS.GSI_fOmitHierPtrs : 0;
                            ErrorHandler.ThrowOnFailure(multiItemSelect.GetSelectedItems(flags, numberOfSelectedItems, vsItemSelections));

                            foreach (VSITEMSELECTION vsItemSelection in vsItemSelections) {
                                yield return new VSITEMSELECTION() { itemid = vsItemSelection.itemid, pHier = hierarchy };
                            }
                        }
                    }
                }
            } finally {
                if (hierarchyPtr != IntPtr.Zero) {
                    Marshal.Release(hierarchyPtr);
                }
                if (selectionContainer != IntPtr.Zero) {
                    Marshal.Release(selectionContainer);
                }
            }
        }

 internal static Guid GetItemType(VSITEMSELECTION vsItemSelection) {
     Guid typeGuid;
     try {
         ErrorHandler.ThrowOnFailure(
             vsItemSelection.pHier.GetGuidProperty(
                 vsItemSelection.itemid,
                 (int)__VSHPROPID.VSHPROPID_TypeGuid,
                 out typeGuid
             )
         );
     } catch (System.Runtime.InteropServices.COMException) {
         return Guid.Empty;
     }
     return typeGuid;
 }

        public void TestSccMenuCommands()
        {
            int result = 0;
            Guid badGuid = new Guid();
            Guid guidCmdGroup = GuidList.guidSccProviderCmdSet;

            OLECMD[] cmdAddToScc = new OLECMD[1];
            cmdAddToScc[0].cmdID = CommandId.icmdAddToSourceControl;
            OLECMD[] cmdCheckin = new OLECMD[1];
            cmdCheckin[0].cmdID = CommandId.icmdCheckin;
            OLECMD[] cmdCheckout = new OLECMD[1];
            cmdCheckout[0].cmdID = CommandId.icmdCheckout;
            OLECMD[] cmdUseSccOffline = new OLECMD[1];
            cmdUseSccOffline[0].cmdID = CommandId.icmdUseSccOffline;
            OLECMD[] cmdViewToolWindow = new OLECMD[1];
            cmdViewToolWindow[0].cmdID = CommandId.icmdViewToolWindow;
            OLECMD[] cmdToolWindowToolbarCommand = new OLECMD[1];
            cmdToolWindowToolbarCommand[0].cmdID = CommandId.icmdToolWindowToolbarCommand;
            OLECMD[] cmdUnsupported = new OLECMD[1];
            cmdUnsupported[0].cmdID = 0;

            // Initialize the provider, etc
            SccProviderService target = GetSccProviderServiceInstance;

            // Mock a service implementing IVsMonitorSelection
            BaseMock monitorSelection = MockIVsMonitorSelectionFactory.GetMonSel();
            serviceProvider.AddService(typeof(IVsMonitorSelection), monitorSelection, true);

            // Commands that don't belong to our package should not be supported
            result = _sccProvider.QueryStatus(ref badGuid, 1, cmdAddToScc, IntPtr.Zero);
            Assert.AreEqual((int)Microsoft.VisualStudio.OLE.Interop.Constants.OLECMDERR_E_NOTSUPPORTED, result);

            // The command should be invisible when there is no solution
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdAddToScc);

            // Activate the provider and test the result
            target.SetActive();
            Assert.AreEqual(true, target.Active, "Microsoft.Samples.VisualStudio.SourceControlIntegration.SccProvider.SccProviderService.Active was not reported correctly.");

            // The commands should be invisible when there is no solution
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdAddToScc);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdCheckin);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdCheckout);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdUseSccOffline);

            // Commands that don't belong to our package should not be supported
            result = _sccProvider.QueryStatus(ref guidCmdGroup, 1, cmdUnsupported, IntPtr.Zero);
            Assert.AreEqual((int)Microsoft.VisualStudio.OLE.Interop.Constants.OLECMDERR_E_NOTSUPPORTED, result);

            // Deactivate the provider and test the result
            target.SetInactive();
            Assert.AreEqual(false, target.Active, "Microsoft.Samples.VisualStudio.SourceControlIntegration.SccProvider.SccProviderService.Active was not reported correctly.");

            // Create a solution
            solution.SolutionFile = Path.GetTempFileName();
            MockIVsProject project = new MockIVsProject(Path.GetTempFileName());
            project.AddItem(Path.GetTempFileName());
            solution.AddProject(project);

            // The commands should be invisible when the provider is not active
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdAddToScc);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdCheckin);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdCheckout);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdUseSccOffline);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdViewToolWindow);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_INVISIBLE, cmdToolWindowToolbarCommand);

            // Activate the provider and test the result
            target.SetActive();
            Assert.AreEqual(true, target.Active, "Microsoft.Samples.VisualStudio.SourceControlIntegration.SccProvider.SccProviderService.Active was not reported correctly.");

            // The command should be visible but disabled now, except the toolwindow ones
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdAddToScc);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdCheckin);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdCheckout);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdUseSccOffline);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_ENABLED, cmdViewToolWindow);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_ENABLED, cmdToolWindowToolbarCommand);

            // Set selection to solution node
            VSITEMSELECTION selSolutionRoot;
            selSolutionRoot.pHier = _solution as IVsHierarchy;
            selSolutionRoot.itemid = VSConstants.VSITEMID_ROOT;
            monitorSelection["Selection"] = new VSITEMSELECTION[] { selSolutionRoot };

            // The add command should be available, rest should be disabled
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_ENABLED, cmdAddToScc);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdCheckin);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdCheckout);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdUseSccOffline);

            // Still solution hierarchy, but other way
            selSolutionRoot.pHier = null;
            selSolutionRoot.itemid = VSConstants.VSITEMID_ROOT;
            monitorSelection["Selection"] = new VSITEMSELECTION[] { selSolutionRoot };

            // The add command should be available, rest should be disabled
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED | OLECMDF.OLECMDF_ENABLED, cmdAddToScc);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdCheckin);
            VerifyCommandStatus(OLECMDF.OLECMDF_SUPPORTED, cmdCheckout);
//.........这里部分代码省略.........

 internal static string Name(VSITEMSELECTION item) {
     return GetItemName(item.pHier, item.itemid);
 }

        /// <summary>
        /// Gets the list of directly selected VSITEMSELECTION objects
        /// </summary>
        /// <returns>A list of VSITEMSELECTION objects</returns>
        private IList<VSITEMSELECTION> GetSelectedNodes()
        {
            // Retrieve shell interface in order to get current selection
            IVsMonitorSelection monitorSelection = _sccProvider.GetService(typeof(IVsMonitorSelection)) as IVsMonitorSelection;

            Debug.Assert(monitorSelection != null, "Could not get the IVsMonitorSelection object from the services exposed by this project");

            if (monitorSelection == null)
            {
                throw new InvalidOperationException();
            }

            List<VSITEMSELECTION> selectedNodes = new List<VSITEMSELECTION>();
            IntPtr hierarchyPtr = IntPtr.Zero;
            IntPtr selectionContainer = IntPtr.Zero;
            try
            {
                // Get the current project hierarchy, project item, and selection container for the current selection
                // If the selection spans multiple hierachies, hierarchyPtr is Zero
                uint itemid;
                IVsMultiItemSelect multiItemSelect = null;
                ErrorHandler.ThrowOnFailure(monitorSelection.GetCurrentSelection(out hierarchyPtr, out itemid, out multiItemSelect, out selectionContainer));

                if (itemid != VSConstants.VSITEMID_SELECTION)
                {
                    // We only care if there are nodes selected in the tree
                    if (itemid != VSConstants.VSITEMID_NIL)
                    {
                        if (hierarchyPtr == IntPtr.Zero)
                        {
                            // Solution is selected
                            VSITEMSELECTION vsItemSelection;
                            vsItemSelection.pHier = null;
                            vsItemSelection.itemid = itemid;
                            selectedNodes.Add(vsItemSelection);
                        }
                        else
                        {
                            IVsHierarchy hierarchy = (IVsHierarchy)Marshal.GetObjectForIUnknown(hierarchyPtr);
                            // Single item selection
                            VSITEMSELECTION vsItemSelection;
                            vsItemSelection.pHier = hierarchy;
                            vsItemSelection.itemid = itemid;
                            selectedNodes.Add(vsItemSelection);
                        }
                    }
                }
                else
                {
                    if (multiItemSelect != null)
                    {
                        // This is a multiple item selection.

                        //Get number of items selected and also determine if the items are located in more than one hierarchy
                        uint numberOfSelectedItems;
                        int isSingleHierarchyInt;
                        ErrorHandler.ThrowOnFailure(multiItemSelect.GetSelectionInfo(out numberOfSelectedItems, out isSingleHierarchyInt));
                        bool isSingleHierarchy = (isSingleHierarchyInt != 0);

                        // Now loop all selected items and add them to the list
                        Debug.Assert(numberOfSelectedItems > 0, "Bad number of selected itemd");
                        if (numberOfSelectedItems > 0)
                        {
                            VSITEMSELECTION[] vsItemSelections = new VSITEMSELECTION[numberOfSelectedItems];
                            ErrorHandler.ThrowOnFailure(multiItemSelect.GetSelectedItems(0, numberOfSelectedItems, vsItemSelections));
                            foreach (VSITEMSELECTION vsItemSelection in vsItemSelections)
                            {
                                selectedNodes.Add(vsItemSelection);
                            }
                        }
                    }
                }
            }
            finally
            {
                if (hierarchyPtr != IntPtr.Zero)
                {
                    Marshal.Release(hierarchyPtr);
                }
                if (selectionContainer != IntPtr.Zero)
                {
                    Marshal.Release(selectionContainer);
                }
            }

            return selectedNodes;
        }

        public static VSITEMSELECTION GetSelectedSourceImage(this IVsMonitorSelection monitorSelection)
        {
            VSITEMSELECTION sel = new VSITEMSELECTION();

            if (monitorSelection != null)
            {
                IntPtr hierarchyPtr = IntPtr.Zero;
                IntPtr selectionContainerPtr = IntPtr.Zero;

                try
                {
                    IVsMultiItemSelect multiSelect;
                    if (monitorSelection.GetCurrentSelection(out hierarchyPtr, out sel.itemid, out multiSelect, out selectionContainerPtr) >= 0)
                    {
                        sel.pHier = Marshal.GetObjectForIUnknown(hierarchyPtr) as IVsHierarchy;
                        if (sel.pHier != null && multiSelect != null)
                        {
                            uint items;
                            int singleHierarchy;
                            if (multiSelect.GetSelectionInfo(out items, out singleHierarchy) >= 0 && items != 1)
                            {
                                // Must have only one item selected
                                sel.pHier = null;
                            }
                        }
                    }
                }
                finally
                {
                    if (hierarchyPtr != IntPtr.Zero)
                    {
                        Marshal.Release(hierarchyPtr);
                        hierarchyPtr = IntPtr.Zero;
                    }

                    if (selectionContainerPtr != IntPtr.Zero)
                    {
                        Marshal.Release(selectionContainerPtr);
                        selectionContainerPtr = IntPtr.Zero;
                    }
                }
            }

            bool isImage = false;

            if (sel.pHier != null)
            {
                object nameObj;
                if (sel.pHier.GetProperty(sel.itemid, (int)__VSHPROPID.VSHPROPID_Name, out nameObj) >= 0)
                {
                    isImage = ImageHelpers.IsSourceImageFile(nameObj as string);
                }
            }

            if (!isImage)
            {
                sel = new VSITEMSELECTION();
            }

            return sel;
        }

        internal static EnvDTE.ProjectItem GetExtensionObject(VSITEMSELECTION selection) {
            object project;

            ErrorHandler.ThrowOnFailure(
                selection.pHier.GetProperty(
                    selection.itemid,
                    (int)__VSHPROPID.VSHPROPID_ExtObject,
                    out project
                )
            );

            return (project as EnvDTE.ProjectItem);
        }

        private void RefreshSourceControlGlyphs(VSITEMSELECTION node)
        {
            var project = node.pHier as IVsSccProject2;
            if (project != null)
            {
                // Refresh all the glyphs in the project; the project will call back GetSccGlyphs()
                // with the files for each node that will need new glyph
                project.SccGlyphChanged(0, null, null, null);
            }
            else if (node.itemid == VSConstants.VSITEMID_ROOT)
            {
                // Note: The solution's hierarchy does not implement IVsSccProject2, IVsSccProject interfaces
                // It may be a pain to treat the solution as special case everywhere; a possible workaround is
                // to implement a solution-wrapper class, that will implement IVsSccProject2, IVsSccProject and
                // IVsHierarhcy interfaces, and that could be used in provider's code wherever a solution is needed.
                // This approach could unify the treatment of solution and projects in the provider's code.

                // Until then, solution is treated as special case
                var sccService = _serviceProvider.GetService<SourceControlProvider>();

                string directory, fileName, userFile;
                ErrorHandler.ThrowOnFailure(_vsSolution.GetSolutionInfo(out directory, out fileName, out userFile));

                var rgpszFullPaths = new[] {fileName};
                var rgsiGlyphs = new VsStateIcon[1];
                sccService.GetSccGlyph(1, rgpszFullPaths, rgsiGlyphs, new uint[1]);

                // Set the solution's glyph directly in the hierarchy
                ((IVsHierarchy)_vsSolution).SetProperty(VSConstants.VSITEMID_ROOT, (int)__VSHPROPID.VSHPROPID_StateIconIndex, rgsiGlyphs[0]);
            }
        }

        private static void AddToNewFile(VSITEMSELECTION item, AddAzureServiceDialog dlg) {
            var code = dlg.GenerateServiceCode();
            var tempFile = Path.GetTempFileName();
            File.WriteAllText(tempFile, code);

            var projectItem = GetProjectItems(item).AddFromTemplate(
                tempFile,
                dlg.ServiceName.Text + ".py"
            );
            var window = projectItem.Open();
            window.Activate();
        }

        internal static EnvDTE.ProjectItems GetProjectItems(VSITEMSELECTION selection) {
            object project;

            ErrorHandler.ThrowOnFailure(
                selection.pHier.GetProperty(
                    selection.itemid,
                    (int)__VSHPROPID.VSHPROPID_ExtObject,
                    out project
                )
            );

            if (project is EnvDTE.ProjectItem) {
                return ((EnvDTE.ProjectItem)project).ProjectItems;
            }
            return ((EnvDTE.Project)project).ProjectItems;
        }

 private static AddAzureServiceDialog CreateAddServiceDialog(VSITEMSELECTION item) {
     switch (GetProjectKind(item)) {
         case ProjectKind.Bottle:
             return new AddAzureServiceDialog("views", true);
         default:
             return new AddAzureServiceDialog(null, false);
     }
 }

 private static bool IsCommandDisabledForFile(VSITEMSELECTION? item) {
     if (item.Value.IsFile() &&
         String.Equals(Path.GetExtension(item.Value.GetCanonicalName()), ".py", StringComparison.OrdinalIgnoreCase)) {
         return false;
     }
     return true;
 }

 public int GetSelectedItems(uint grfGSI, uint cItems, VSITEMSELECTION[] rgItemSel) {
     var flags = (__VSGSIFLAGS)grfGSI;
     for (int i = 0; i < cItems && i < _items.Length; i++) {
         rgItemSel[i].itemid = _items[i].ItemId;
         if (!flags.HasFlag(__VSGSIFLAGS.GSI_fOmitHierPtrs)) {
             rgItemSel[i].pHier = _items[i].Hierarchy;
         }
     }
     return VSConstants.S_OK;
 }

 int IVsSimpleObjectList2.GetMultipleSourceItems(uint index, uint grfGSI, uint cItems, VSITEMSELECTION[] rgItemSel)
 {
     return VSConstants.E_NOTIMPL;
 }

        /// <summary>
        /// Gets the list of selected HierarchyNode objects
        /// </summary>
        /// <returns>A list of HierarchyNode objects</returns>
        protected internal virtual IList<HierarchyNode> GetSelectedNodes()
        {
            // Retrieve shell interface in order to get current selection
            IVsMonitorSelection monitorSelection = this.GetService(typeof(IVsMonitorSelection)) as IVsMonitorSelection;

            if (monitorSelection == null)
            {
                throw new InvalidOperationException();
            }

            List<HierarchyNode> selectedNodes = new List<HierarchyNode>();
            IntPtr hierarchyPtr = IntPtr.Zero;
            IntPtr selectionContainer = IntPtr.Zero;
            try
            {
                // Get the current project hierarchy, project item, and selection container for the current selection
                // If the selection spans multiple hierachies, hierarchyPtr is Zero
                uint itemid;
                IVsMultiItemSelect multiItemSelect = null;
                ErrorHandler.ThrowOnFailure(monitorSelection.GetCurrentSelection(out hierarchyPtr, out itemid, out multiItemSelect, out selectionContainer));

                // We only care if there are one ore more nodes selected in the tree
                if (itemid != VSConstants.VSITEMID_NIL && hierarchyPtr != IntPtr.Zero)
                {
                    IVsHierarchy hierarchy = Marshal.GetObjectForIUnknown(hierarchyPtr) as IVsHierarchy;

                    if (itemid != VSConstants.VSITEMID_SELECTION)
                    {
                        // This is a single selection. Compare hirarchy with our hierarchy and get node from itemid
                        if (Utilities.IsSameComObject(this, hierarchy))
                        {
                            HierarchyNode node = this.NodeFromItemId(itemid);
                            if (node != null)
                            {
                                selectedNodes.Add(node);
                            }
                        }
                        else
                        {
                            NestedProjectNode node = this.GetNestedProjectForHierarchy(hierarchy);
                            if (node != null)
                            {
                                selectedNodes.Add(node);
                            }
                        }
                    }
                    else if (multiItemSelect != null)
                    {
                        // This is a multiple item selection.

                        //Get number of items selected and also determine if the items are located in more than one hierarchy
                        uint numberOfSelectedItems;
                        int isSingleHierarchyInt;
                        ErrorHandler.ThrowOnFailure(multiItemSelect.GetSelectionInfo(out numberOfSelectedItems, out isSingleHierarchyInt));
                        bool isSingleHierarchy = (isSingleHierarchyInt != 0);

                        // Now loop all selected items and add to the list only those that are selected within this hierarchy
                        if (!isSingleHierarchy || (isSingleHierarchy && Utilities.IsSameComObject(this, hierarchy)))
                        {
                            Debug.Assert(numberOfSelectedItems > 0, "Bad number of selected itemd");
                            VSITEMSELECTION[] vsItemSelections = new VSITEMSELECTION[numberOfSelectedItems];
                            uint flags = (isSingleHierarchy) ? (uint)__VSGSIFLAGS.GSI_fOmitHierPtrs : 0;
                            ErrorHandler.ThrowOnFailure(multiItemSelect.GetSelectedItems(flags, numberOfSelectedItems, vsItemSelections));
                            foreach (VSITEMSELECTION vsItemSelection in vsItemSelections)
                            {
                                if (isSingleHierarchy || Utilities.IsSameComObject(this, vsItemSelection.pHier))
                                {
                                    HierarchyNode node = this.NodeFromItemId(vsItemSelection.itemid);
                                    if (node != null)
                                    {
                                        selectedNodes.Add(node);
                                    }
                                }
                            }
                        }
                    }
                }
            }
            finally
            {
                if (hierarchyPtr != IntPtr.Zero)
                {
                    Marshal.Release(hierarchyPtr);
                }
                if (selectionContainer != IntPtr.Zero)
                {
                    Marshal.Release(selectionContainer);
                }
            }

            return selectedNodes;
        }