With the release of Visual Studio 2017, some popular database tools such as MySQL no longer appear in the Data Connections node of the Server Explorer even if you have installed current version of MySQL for Visual Studio 1.2.6:

It’s no wonder since if you select the Custom installation you will see that Visual Studio 2017 doesn’t appear yet in the list of possible Visual Studio versions to integrate with:

There is also some bad news: the integration with Visual Studio 2017 is more difficult than in previous versions. Third party database tools had two ways to integrate with Visual Studio using Data Designer Extensibility (DDEX):

The first one, which was valid until Visual Studio 2015, is to create some entries in the Windows Registry. See Registering a Registry-Based DDEX Provider. For data providers and data sources the entries are:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\VisualStudio\<version>\DataProviders
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\VisualStudio\<version>DataSources
Visual Studio merges later and redirects at run-time HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\VisualStudio\<version> to HKEY_CURRENT_USER\SOFTWARE\Microsoft\VisualStudio\<version>_Config, but that’s transparent for the tool.

Since Visual Studio 2017 uses its own private Registry hive (see the Change: Reduce registry impact > Visual Studio registry section of Changes in Visual Studio 2017 extensibility) instead of the Registry entries similar to the ones used by older Visual Studio versions, the previous approach is no longer valid. If the setup of a DDEX provider uses RegLoadAppKey to create entries in that private Registry hive, Visual Studio could wipe out them later when it needs to generate its private Registry hive from .pkgdef files. So, for Visual Studio 2017, the only way is to use .pkgdef files, as explained next.

The second one is to create a .vsix extension (package) that provides enhanced design-time support and uses a .pkgdef file to create those registry entries. See Registering a Package-Based DDEX Provider. This is the approach used by MySQL. For Visual Studio 2015 you can see that it installs an extension in the folder:
C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Oracle\MySQL for Visual Studio\1.2.6.

In that folder you can find the MySql.VisualStudio.pkgdef that creates the registry entries:

So, Oracle needs to modify the MySQL package to support Visual Studio 2017. Alas, their vsix manifest is still using version 1.0:

and that is because they wanted to support Visual Studio 2010, 2012, 2013 and 2015 with a single .vsix file:

• Visual Studio 2010 only supports manifests with version 1.0.
• Version 2.0 was introduced by Visual Studio 2012, and it is not backwards compatible, so Visual Studio 2010 doesn’t support it.
• While Visual Studio 2012, 2013 and 2015 support manifests with version 2.0, they also support manifests with version 1.0. So a single .vsix can target Visual Studio 2010, 2012, 2013 and 2015.
• Visual Studio 2017 doesn’t support manifests with version 1.0. So, it is not possible to have a single .vsix for Visual Studio 2010, 2012, 2013, 2015 and 2017.
• Instead, Visual Studio 2017 requires a manifest with version 3.0.
• Fortunately, version 3.0 is backwards compatible with version 2.0 (version 3.0 adds a Xml entry that is only recognized by Visual Studio 2017 and ignored by previous versions. See section Changes Affecting VSIX Format and Installation). So, a single .vsix can target Visual Studio 2012, 2013, 2015 and 2017.

The bottom line is that two installers will be required for MySQL to target the last five versions of Visual Studio 2010-2017. It’s a pity that Oracle hasn’t used the previous months to make all these changes, frustrating its users.

Answering a question in the MSDN VSX forum today, I have learned another change caused by the new VSIX installer (VSIXInstaller.exe) of Visual Studio 2017 that it is worth documenting here.

As you know, in Visual Studio 2015 only one edition (Community, Professional or Enterprise) could be installed on the same machine. Two or more editions couldn’t coexist at the same time. Given that the Enterprise edition includes the features of the Professional edition and that the Community edition is basically the Professional Edition (without some feature such as CodeLens), the VSIX manifest of your extension could target the “Pro” edition and as such it would be installable on any edition (Community, Professional or Enterprise):

Normally a .VSIX file is installed just double-clicking it, so that the VSIXInstaller.exe application is launched. But if you want to install an extension programatically, the VSIXInstaller.exe application offers a few command-line switches:

Notice the /skuName:<name> option: it allows to specify the exact edition (Enterprise, Premium, Pro, Community, etc.) of Visual Studio where you want to install the extension. Which value you would need to use? It happens that for Visual Studio 2015, you can use “Pro” and the extension will be installed happily not only on Visual Studio 2015 Professional, but also on Visual Studio 2015 Community or  (Updated March 1, see comments section) Visual Studio 2015 Enterprise. For example, installing my MZ-Tools extension on Visual Studio 2015 Enterprise edition with this command line works perfectly:

vsixinstaller.exe /skuName:Pro /skuVersion:14.0 “<path>\MZTools8VSPackage.vsix”

(notice that it recognizes my Enterprise edition as Professional edition).

However, the same is not true for VS 2017. Using this command line to install it on my Visual Studio 2017 Enterprise edition:

vsixinstaller.exe /skuName:Pro /skuVersion:15.0 “<path>\MZTools8VSPackage.vsix”

causes this error:

The following command-line is required, targeting specifically the Enterprise edition:

vsixinstaller.exe /skuName:Enterprise /skuVersion:15.0 “<path>\MZTools8VSPackage.vsix”

So, this is another implication of the new modular setup of Visual Studio 2017 for VSX developers. You can query the installed VS 2017 editions with a new Setup API (sample included).

Justin Clareburt, Program Manager in Visual Studio Extensibility, and super passionate about VSX and super active in the Microsoft/extendvs Gitter room to help you to update successfully your extension to Visual Studio 2017, has also time to produce videos and to create extensions!:

The first video is with Seth Juarez, about using keyboard mappings in Visual Studio:

And his “hot” extensions:

– Hot Keys: Visual Studio Extension that imports several new keyboard mapping schemes http://aka.ms/hotkeys

– Hot Commands: Provides additional commands and shortcuts for enhanced productivity http://aka.ms/hotcommands

The second video is with Robert Green (Visual Studio Toolbox) about updating your extension to the new Visual Studio 2017:

Just in case you haven’t noticed it, the NuGet package for Microsoft.VSSDK.BuildTools 15.0 is no longer Preview or Release Candidate (RC, RC2 or RC3) but final release:

As you can see, it has been a long way of previews / RCs to reach this point:

So, it’s time to update that NuGet package and rebuild. Microsoft hasn’t announced yet the release date of the final version of Visual Studio 2017 but it seems that we are approaching that date, at least from the Visual Studio Extensibility point of view. Update (Feb 10): the launch date has been announced for March 7. If you haven’t updated your extension to support VS 2017 yet, the clock is ticking. Here you have the guidance to do it.

I still see, even as today Jan 10, people asking why you get this error when trying to install your extension on Visual Studio 2017 RC:

“The following extensions are not compatible with Visual Studio 15. Installation may cause Visual Studio to be unstable”:

or this other one when you try to upload the extension to the Visual Studio Gallery:

“This extension targets Visual Studio 2017 but was not build with an up-to-date VSSDK. Please make sure to update your references and try uploading again. Note: you’ll also need to add Prerequisites to your extension.vsixmanifest.”:

In both cases, the answer is the same: you have just updated the extension.vsixmanifest of your Visual Studio 2015 extension to add 15.0 (for Visual Studio 2017):

 <Installation>
 <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[14.0, 15.0]" />
 </Installation>

But that is not enough to add compatibility for Visual Studio 2017. Even worse, some people wonder if you can live ignoring those warnings.

The short answer to make an extension compatible with Visual Studio 2017 is the following:

• You need to build it with Visual Studio 2017, you cannot use Visual Studio 2015 (at least at this time). Updated (Feb 7): actually you can build with VS 2015. Updated (Mar 3): as explained in the FAQ entry Can I build a VSIX v3 with Visual Studio 2015?
• You need an updated pre-release VS SDK (via NuGet). Updated (Feb 7): The Nuget VSSDK 15.0 is no longer prerelease. This VS SDK generates two additional files (catalog.json and manifest.json) inside the output .vsix file (which being a .zip file really, you can rename and unzip to inspect) that were not present in the .vsix generated by the VS 2015 SDK.
• You need to update the InstallationTarget range in the extension.vsixmanifest (likely this is the only thing that you have done).
• You need to convert the extension.vsixmanifest to version 3, which is the only version that Visual Studio 2017 accepts (and the Visual Studio Gallery for extensions targeting Visual Studio 2017). Version 3 is backwards compatible with version 2, which means that all fields are the same (including the Version=”2.0.0″!). The only difference is that version 3.0 adds a mandatory section for the prerequisites. At the very least you need to specify the Visual Studio Core Editor (Visual Studio 2017 has an editor to enter values in a friendly way):

<Prerequisites>
   <Prerequisite Id="Microsoft.VisualStudio.Component.CoreEditor" Version="[15.0.25904.2,16.0)" DisplayName="Visual Studio core editor" />
</Prerequisites>

The long answer, with links to resources is on my post Visual Studio 2017 RC announced. Extensions need some changes, and for advanced topics read Some implications of the new modular setup of Visual Studio 2017 for VSX developers.

Now, once that you have assumed that you need a v3 VSIX manifest for Visual Studio 2017, you may wonder how to support multiple instances of Visual Studio from VS 2010 to VS 2017 with the same .vsix: you can’t, because VS 2010 only accepts manifest v1, while VS 2012, VS 2013 and VS 2015 accept manifest v1, v2 or v3 (backwards compatible with v2), and VS 2017 only accepts manifest v3. You need two .vsix files. So, you have two choices:

• Create a VSIX with manifest v1 for VS 2010, VS 2012, VS 2013 and VS 2015, and another VSIX with manifest v3 for VS 2017. This is the most suggested approach, but there is a better one.
• Create a VSIX with manifest v1 for VS 2010, VS 2012 and VS 2013, and another VSIX with manifest v3 for VS 2015 and VS 2017. Why? Because VS 2015 introduced APIs not available in previous versions that you can use in VS 2015 and VS 2017 to make your extension a better citizen, such as How to: Use AsyncPackage to Load VSPackages in the Background and How to: Use Rule-based UI Context for Visual Studio Extensions.
• Updated (Feb 7): if you are not targeting VS 2010 but only VS 2012 and higher, you can have a single VSIX using v3 for VS 2012, 2013, 2015 and 2017.

To get support from Microsoft, you can become a Microsoft Visual Studio Industry Partner (VSIP) “Basic” level for free and get access to workshops explaining the migration process, or you can use Gitter (Microsoft/extendvs), where people from Microsoft and other VSX developers answer questions, the MSDN Visual Studio Integrate Forum that I visit daily, or StackOverflow. And if you find bugs or want to provide suggestions to Microsoft, you can also send feedback to Microsoft about Visual Studio Extensibility through several ways.

As you may already know, VS 2017 (formerly VS “15”) introduces a couple of very welcomed changes:

• It provides a new modular setup that allows you to decide which tools (“workloads”) you want to install and, most importantly, which ones you don’t want at all. The consequence is that installing VS 2017 is much, much faster (unless you install a lot of workloads, of course). This suggestion had almost 2,000 votes on UserVoice. For VSX developers like me that already have six versions of Visual Studio installed (from VS 2005 to VS 2015) on the main dev machine (not counting isolated installations on virtual machines) and know how painful each installation is, this is big news.
• Visual Studio 2017 allows to coexist several editions on the same machine. So, you can have VS 2017 Community Edition, VS 2017 Professional Edition and VS 2017 Enterprise Edition. This may not be very useful for end users, but for VSX developers it allows you to test your extension (which needs to declare the minimum supported edition in the Vsix manifest) on the three editions on the same computer. Here you can see my computer with the Community edition installed (notice the familiar “Common7” folder inside the “Microsoft Visual Studio\2017\Community” folder):

If you want the details about the new setup experience, the official posts from Microsoft about this on the Visual Studio blog are the following:

Faster, Leaner, Focused on Your Development Needs: The New Visual Studio Installer

Visual Studio “15”: Installing Just What You Need

Anatomy of a Low Impact Visual Studio Install

On the Road to Release: Redesigning Visual Studio Installation

Visual Studio “15” Preview 4

But not only that. Visual Studio 2017 is also much more isolated and resilient. It doesn’t install Visual Studio assemblies in the Global Assembly Cache (GAC) and it doesn’t use for the most part the main Windows Registry. In the past (since VS 2010, see my post The strange case of the registry key HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\10.0_Config\Projects\{C8D11400-126E-41CD-887F-60BD40844F9E}), Visual Studio redirected HKEY_LOCAL_MACHINE\Software\Microsoft\VisualStudio\<version> to HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\<version>_Config, to allow installation of extensions through .pkgdef files without admin rights, etc. Now, VS 2017 uses its own private registry. See how empty is the regular HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\15.0 key on my machine and notice that there is no 15.0_Config key:

Instead, the VS 2017 private registry is stored in your AppData folder:

Fortunately, you can use regedit.exe to load a private hive. You need to select the HKEY_USERS node, and click the File > Load Hive… menu. You select the privateregistry.bin file, give a name to the hive (I entered “VS2017PrivateRegistry”) and now you can see the 15.0<id>_Config key populated as usual (note: use File > Unload Hive when done):

Hopefully all this isolation and resilience can prevent the problems that I suffered with VS 2015 when my Surface Pro 4 crashed at boot time due to a buggy antivirus update (I never recovered VS 2015).

So far, so good, but all this will cause some issues to VSX developers. I adapted my MZ-Tools extension to run in Visual Studio 2017 some weeks ago and I am these days migrating my old .NET-based custom builder for MZ-Tools to fully embrace MSBuild and hopefully to use a separate Windows Azure build server, better environment/workspaces isolation, etc.

The changes above can cause some trouble:

• The location of devenv.exe for Visual Studio 2017 has changed, and can be several of them.
  As explained above, you can have now several Visual Studio 2017 installations on your machine. In the past (until Visual Studio 2015) you could query the HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\VisualStudio\14.0, InstallDir entry, to get the (only) installation folder for Visual Studio (2015). Now, there can be several Visual Studio 2017 installation folders (Community, Professional, Enterprise), and you cannot query the registry directly. Instead, the official approach is to use some interop assemblies (Microsoft.VisualStudio.Setup.Configuration.Interop) provided by Microsoft to enumerate the Visual Studio 2017 installations. See the post Changes to Visual Studio “15” Setup and the Microsoft/vs-setup-samples samples on GitHub. Of course, for your own use on your own build script you can hardcode paths ;-).
• External processes cannot read Visual Studio 2017 registry entries directly.
  Extensions can read Visual Studio 2017 registry entries from the private registry in a transparent way, because being dlls, they run in-process with devenv.exe and leverage the redirection provided by Visual Studio. But out-of-process executables or scripts need to use the  RegLoadAppKey function. See the section “Change: Reduce registry impact” in Breaking Changes in Visual Studio 2017 extensibility.
• The location of MSBuild for VS 2017 has changed, and can be several of them.
  In the past (until Visual Studio 2015), the path of MSBuild was “C:\Program Files (x86)\MSBuild\<version>”, where <version> was “4.0”, “12.0” (VS 2013), “14.0” (VS 2015). There is no “15.0” folder there for VS 2017. Instead, MSBuild for VS 2017 is installed in the folder “C:\Program Files (x86)\Microsoft Visual Studio\2017\<edition>\MSBuild\15.0”, where edition can be “Community”, “Professional” or “Enterprise”. Again, for your own use on your own build script you can hardcode the path, but if you want to use a more proper way, you need to get the VS 2017 installation folder as explained above and concatenate “MSBuild\15.0”. Or you can wait until Microsoft releases a document about how to resolve MSBuild location (they are working on it and now that MSBuild is open source you can follow the progress on GitHub). BTW, you can download the MSBuild Tools for Visual Studio 2017 RC here.
• The location of tf.exe (Team Explorer command-line) has changed.
  In the past, for Visual Studio 2013 and 2015 it was stored in the folder C:\Program Files (x86)\Microsoft Visual Studio <version>\Common7\IDE. For Visual Studio 2017, it is installed in the folder of the Team Explorer extension (C:\Program Files (x86)\Microsoft Visual Studio\2017\<edition>\Common7\IDE\Extensions\<random folder>). Fortunately, there is a shortcut in the folder C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer that point to that location. Did I mention that there can be several editions of Visual Studio 2017 installed?
• The VsWebSite.Interop.dll automation file is not included in the Core Editor and causes FileNotFoundException.
  The EnvDTE automation assemblies don’t provide extensibility for all kind of projects (for example, you cannot get project references for VB/C# projects with that assembly). For VB/C# projects, you need the VSLangProj.dll family of assemblies. Both EnvDTE and VSLangProj are included by default with the Core Editor of Visual Studio 2017 and therefore your extension will work just declaring Visual Studio Code Editor as dependency in the new Vsix Manifest editor for version 3:
  Those assemblies are also valid for Web Application projects. However, Visual Studio 2005 introduced Web Site projects, that lack a project file and Microsoft provided the VsWebSite.Interop.dll family of assemblies to deal with that kind of projects using automation (for example, to get their references). Alas, the VsWebSite.Interop.dll assembly is not included in the core editor, and therefore each time that a method of your extension uses its types (when the method is JIT-compiled) will cause FileNotFoundException. For example a method with this code:

foreach (EnvDTE.Project project in solution.Projects)
{
   langProject = project.Object as VSLangProj.VSProject;
   if (langProject != null)
   {
   ...
   }
   else
   {
       webProject = project.Object as VsWebSite.VSWebSite;
       if (webProject != null)
       {
       ...
       }
   }
}

I reported this to Microsoft through private channels and on Microsoft Connect (VsWebSite.Interop.dll extensibility assembly not installed by Visual Studio core editor) and the only answer so far has been that the extension must declare a dependency on the Microsoft.VisualStudio.WebTools (which installs that assembly), but that is not a solution for me since:

1) That component installs tons of files related to web development, not only VsWebSite.Interop.dll. The user should not be forced to install web-related stuff (project templates, etc.) that she doesn’t require and that would dirty the Visual Studio installation for that simple extension to work.

2) Even if only VsWebSite.Interop.dll was installed by that Microsoft.VisualStudio.WebTools component it would be annoying for users to install that component.

It is a good thing that Microsoft uses EnvDTE / VSLangProj internally and therefore they needed to include them in the Core Editor. Otherwise they wouldn’t be there either. You know that I am not very fan of EnvDTE/VSLangProj although I still use them very heavily (Microsoft has insisted that they are not going to disappear or be deprecated).

Fortunately, there is a workaround, that is what I used. I refactored the methods of MZ-Tools that use the types of VsWebSite.Interop.dll to move the code inside the method that uses the types to a new method and then handled gracefully the FileNotFoundException. For example:

public Collection References
{
   get
   {
      Collection references = new Collection();

      AddLangProjReferences(references);

      if (references.Count == 0)
      {
         try
         {
            AddWebSiteReferences(references);
         }
         catch (System.IO.FileNotFoundException)
         {
            // This can happen in VS 2017 if the web development workload is not installed 
         }
      }
      return references;
   }
}

I hope this post helps you. Happy coding!