HOWTO: Get the project flavor (subtype) of a Visual Studio project from an add-in

Author:	Carlos J. Quintero (Microsoft MVP)	Applies to:	Microsoft Visual Studio 2005
Date:	February 2007

Introduction

Visual Studio projects have a project type (such as VB.NET project, C# project, etc.) and each project type can have a flavor (or subtype), which is a specialized project based on the project type to customize its behavior without forcing to create a whole new project type. For example, you can have Test projects, which are based on the VB.NET or C# project types, but are specialized to create and run tests. You can learn more about project types and project subtypes in the Visual Studio 2005 SDK, sections Project Types and Project Subtypes.

Project types and subtypes are identified by Guids. The extensibility model for add-ins (EnvDTE.dll) allows you to know the Guid of the project type using the EnvDTE.Project.Kind property, but it does not allow you to get the Guid of the project subtype. This article explains how to get it using a service from the IDE.

More Information
Visual Studio stores in the .vbproj or .csproj file the project type and subtype Guids of a project. For example, if you open with a text editor a Test Project file created with VB.NET, you will find this XML entry:

<ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{F184B08F-C81C-45F6-A57F-5ABD9991F28F}</ProjectTypeGuids>

The list of Guids for projects types and subtypes supported by your Visual Studio installation is in this registry entry:

HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/VisualStudio/8.0/Projects

where we see that the Guid {F184B08F-C81C-45F6-A57F-5ABD9991F28F} matches a VB.NET project (the project type) and the Guid {3AC096D0-A1C2-E12C-1390-A8335801FDAB} matches the Test Project subtype. See the article INFO: List of known project type Guids.

The EnvDTE.Project.Kind property returns the project type ({F184B08F-C81C-45F6-A57F-5ABD9991F28F} in this case for the Test Project) and there is no way using the extensibility model to get the project subtype. Fortunately you can use services from the IDE as explained in the article HOWTO: Get a Visual Studio service from an add-in. Specifically, we can use the Microsoft.VisualStudio.Shell.Interop.IVsAggregatableProject interface and its GetAggregateProjectTypeGuids method as shown below (VB.NET code). You will need to add references to the following assemblies (see the article HOWTO: Reference a Visual Studio assembly in the GAC from an add-in):

Microsoft.VisualStudio.OLE.Interop

Microsoft.VisualStudio.Shell.Interop

Microsoft.Visualstudio.Shell.Interop.8.0

Given an EnvDTE.Project, the following function returns a list of project type and subtype Guids separated by ";" that you can then split into individual Guids:

Public Function GetProjectTypeGuids(ByVal proj As EnvDTE.Project) As String

Dim sProjectTypeGuids As String = ""
Dim objService As Object
Dim objIVsSolution As Microsoft.VisualStudio.Shell.Interop.IVsSolution
Dim objIVsHierarchy As Microsoft.VisualStudio.Shell.Interop.IVsHierarchy = Nothing
Dim objIVsAggregatableProject As Microsoft.VisualStudio.Shell.Interop.IVsAggregatableProject
Dim iResult As Integer

objService = GetService(proj.DTE, GetType(Microsoft.VisualStudio.Shell.Interop.IVsSolution))
objIVsSolution = CType(objService, Microsoft.VisualStudio.Shell.Interop.IVsSolution)

iResult = objIVsSolution.GetProjectOfUniqueName(proj.UniqueName, objIVsHierarchy)

If iResult = 0 Then

objIVsAggregatableProject = CType(objIVsHierarchy, Microsoft.VisualStudio.Shell.Interop.IVsAggregatableProject)

iResult = objIVsAggregatableProject.GetAggregateProjectTypeGuids(sProjectTypeGuids)

End If

Return sProjectTypeGuids

End Function

Public Function GetService(ByVal serviceProvider As Object, ByVal type As System.Type) As Object

Return GetService(serviceProvider, type.GUID)

End Function

Public Function GetService(ByVal serviceProvider As Object, ByVal guid As System.Guid) As Object

Dim objService As Object = Nothing
Dim objIServiceProvider As Microsoft.VisualStudio.OLE.Interop.IServiceProvider
Dim objIntPtr As IntPtr
Dim hr As Integer
Dim objSIDGuid As Guid
Dim objIIDGuid As Guid

objSIDGuid = guid
objIIDGuid = objSIDGuid

objIServiceProvider = CType(serviceProvider, Microsoft.VisualStudio.OLE.Interop.IServiceProvider)

hr = objIServiceProvider.QueryService(objSIDGuid, objIIDGuid, objIntPtr)

If hr <> 0 Then

System.Runtime.InteropServices.Marshal.ThrowExceptionForHR(hr)

ElseIf Not objIntPtr.Equals(IntPtr.Zero) Then

objService = System.Runtime.InteropServices.Marshal.GetObjectForIUnknown(objIntPtr)
System.Runtime.InteropServices.Marshal.Release(objIntPtr)

End If

Return objService

End Function