Persisting the Property of a Project Item

You may want to persist a property you add to a project item, such as the author of a source file. You can do this by storing the property in the project file.

The first step to persist a property in a project file is to obtain the hierarchy of the project as an IVsHierarchy interface. You can obtain this interface either by using Automation or by using IVsMonitorSelection. Once you obtain the interface, you can use it to determine which project item is currently selected. Once you have the project item ID, you can use SetItemAttribute to add the property.

In the following procedures, you persist the VsPkg.cs property Author with the value Tom in the project file.

To obtain the project hierarchy with the DTE object

1. Add the following code to your VSPackage:

   EnvDTE.DTE dte = (EnvDTE.DTE)Package.GetGlobalService(typeof(EnvDTE.DTE));  
   EnvDTE.Project project = dte.Solution.Projects.Item(1);  
   
   string uniqueName = project.UniqueName;  
   IVsSolution solution = (IVsSolution)Package.GetGlobalService(typeof(SVsSolution));  
   IVsHierarchy hierarchy;  
   solution.GetProjectOfUniqueName(uniqueName, out hierarchy);  
   

To persist the project item property with the DTE object

1. Add the following code to the code given in the method in the previous procedure:

   IVsBuildPropertyStorage buildPropertyStorage =   
       hierarchy as IVsBuildPropertyStorage;  
   if (buildPropertyStorage != null)  
   {  
       uint itemId;  
       string fullPath = (string)project.ProjectItems.Item(  
           "VsPkg.cs").Properties.Item("FullPath").Value;  
       hierarchy.ParseCanonicalName(fullPath, out itemId);  
       buildPropertyStorage.SetItemAttribute(itemId, "Author", "Tom");  
   }  
   

To obtain the project hierarchy using IVsMonitorSelection

1. Add the following code to your VSPackage:

   IVsHierarchy hierarchy = null;  
   IntPtr hierarchyPtr = IntPtr.Zero;  
   IntPtr selectionContainer = IntPtr.Zero;  
   uint itemid;  
   
   // Retrieve shell interface in order to get current selection  
   IVsMonitorSelection monitorSelection =     Package.GetGlobalService(typeof(SVsShellMonitorSelection)) as     IVsMonitorSelection;  
   if (monitorSelection == null)  
       throw new InvalidOperationException();  
   
   try  
   {  
       // Get the current project hierarchy, project item, and selection container for the current selection  
       // If the selection spans multiple hierachies, hierarchyPtr is Zero  
       IVsMultiItemSelect multiItemSelect = null;  
       ErrorHandler.ThrowOnFailure(  
           monitorSelection.GetCurrentSelection(  
               out hierarchyPtr, out itemid,   
               out multiItemSelect, out selectionContainer));  
   
       // We only care if there is only one node selected in the tree  
       if (!(itemid == VSConstants.VSITEMID_NIL ||   
           hierarchyPtr == IntPtr.Zero ||  
           multiItemSelect != null ||  
           itemid == VSConstants.VSITEMID_SELECTION))  
       {  
           hierarchy = Marshal.GetObjectForIUnknown(hierarchyPtr)  
               as IVsHierarchy;  
       }  
   }  
   finally  
   {  
       if (hierarchyPtr != IntPtr.Zero)  
           Marshal.Release(hierarchyPtr);  
       if (selectionContainer != IntPtr.Zero)  
           Marshal.Release(selectionContainer);  
   }  
   

To persist the selected project item property, given the project hierarchy

1. Add the following code to the code given in the method in the previous procedure:

   IVsBuildPropertyStorage buildPropertyStorage =   
       hierarchy as IVsBuildPropertyStorage;  
   if (buildPropertyStorage != null)  
   {  
       buildPropertyStorage.SetItemAttribute(itemId, "Author", "Tom");  
   }  
   

To verify that the property is persisted

1. Start Visual Studio and then open or create a solution.

2. Select the project item VsPkg.cs in Solution Explorer.

3. Use a breakpoint or otherwise determine that your VSPackage is loaded and that SetItemAttribute runs.

   Note

   You can autoload a VSPackage in the UI context SolutionExists_guid. For more information, see Loading VSPackages.

4. Close Visual Studio and then open the project file in Notepad. You should see the <Author> tag with the value Tom, as follows:

   <Compile Include="VsPkg.cs">  
       <Author>Tom</Author>  
   </Compile>  
   

See Also

Custom Tools