How to: Persist 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 by using Automation

• Add the following code to your VSPackage:

  Dim dte As EnvDTE.DTE = CType(Package.GetGlobalService(GetType(EnvDTE.DTE)), EnvDTE.DTE)
  Dim project As EnvDTE.Project = dte.Solution.Projects.Item(1)
  
  Dim uniqueName As String = project.UniqueName
  Dim solution As IVsSolution = CType(Package.GetGlobalService(GetType(SVsSolution)), IVsSolution)
  Dim hierarchy As IVsHierarchy
  solution.GetProjectOfUniqueName(uniqueName, hierarchy)
  

  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 by using Automation

• Add the following code to the code given in the method in the previous procedure:

  Dim buildPropertyStorage As IVsBuildPropertyStorage = CType(hierarchy, IVsBuildPropertyStorage)
  If Not buildPropertyStorage Is Nothing Then
      Dim itemId As UInteger
      Dim fullPath As String = CType(project.ProjectItems.Item("VsPkg.vb").Properties.Item("FullPath").Value, String)
      hierarchy.ParseCanonicalName(fullPath, itemId)
      buildPropertyStorage.SetItemAttribute(itemId, "Author", "Tom")
  End If
  

  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 by using IVsMonitorSelection

1. Add the following code to your VSPackage:

   Dim hierarchy As IVsHierarchy = Nothing
   Dim hierarchyPtr As IntPtr = IntPtr.Zero
   Dim selectionContainer As IntPtr = IntPtr.Zero
   Dim itemId As UInteger
   
   ' Retrieve shell interface in order to get current selection
   Dim monitorSelection As IVsMonitorSelection = CType(Package.GetGlobalService(GetType(SVsShellMonitorSelection)), IVsMonitorSelection)
   If monitorSelection Is Nothing Then
       Throw New InvalidOperationException
   End If
   
   Try
       ' Get the current project hierarchy, project item, and selection container for the current selection
       ' If the selection spans multiple hierarchies, hierarchyPtr is Zero
       Dim multiItemSelect As IVsMultiItemSelect = Nothing
       ErrorHandler.ThrowOnFailure(monitorSelection.GetCurrentSelection(
                                   hierarchyPtr, itemId, multiItemSelect, selectionContainer))
   
       ' We only care if there is only one node selected in the tree
       If Not (itemId = VSConstants.VSITEMID.Nil _
               Or hierarchyPtr = IntPtr.Zero _
               Or (Not multiItemSelect Is Nothing) _
               Or itemId = VSConstants.VSITEMID.Selection) Then
           hierarchy = CType(Marshal.GetObjectForIUnknown(hierarchyPtr), IVsHierarchy)
       End If
   Finally
       If hierarchyPtr <> IntPtr.Zero Then
           Marshal.Release(hierarchyPtr)
       End If
       If selectionContainer <> IntPtr.Zero Then
           Marshal.Release(selectionContainer)
       End If
   End Try
   

   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

• Add the following code to the code given in the method in the previous procedure:

  Dim buildPropertyStorage As IVsBuildPropertyStorage = CType(hierarchy, IVsBuildPropertyStorage)
  If Not buildPropertyStorage Is Nothing Then
      buildPropertyStorage.SetItemAttribute(itemId, "Author", "Tom")
  End If
  

  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.

   Hinweis

   You can autoload a VSPackage in the UI context UICONTEXT_SolutionExists. For more information, see How to: Autoload a VSPackage.

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

Other Resources

Project Items (Visual Studio SDK)