I’m often asked how to best learn to build Visual Studio extensions, so here is what I wished someone told me before I got started.

Don’t skip the introduction

It’s easy to create a new extensibility project in Visual Studio, but unless you understand the basics of how the extensibility system works, then you are setting yourself up for failure.

The best introduction I know of is a session from //build 2016 and it is as relevant today as it was then.

Know the resources

Where do you get more information about the various aspects of the Visual Studio APIs you wish to use? Here are some very helpful websites that are good to study.

Know how to search for help

Writing extensions is a bit of a niche activity so searching for help online doesn’t always return relevant results. However, there are ways we can optimize our search terms to generate better results.

  • Use the precise interface and class names as part of the search term
  • Try adding the words VSIX, VSSDK or Visual Studio to the search terms
  • Search directly on GitHub instead of Google/Bing when possible
  • Ask questions to other extenders on the Gitter.im chatroom

Use open source as a learning tool

You probably have ideas about what you want your extension to do and how it should work. But what APIs should you use and how do you hook it all up correctly? These are difficult questions and a lot of people give up when these go unanswered.

The best way I know of is to find extensions on the Marketplace that does similar things or uses similar elements as to what you want to do. Then find the source code for that extension and look at what they did and what APIs they used and go from there.

Additional tools

There is an open source extension for Visual Studio that provides additional features for extension authors that I can highly recommend. Grab the Extensibility Tools extension on the Marketplace.

Also, a NuGet package exist containing Roslyn Analyzers that will help you writing extensions. Add the Microsoft.VisualStudio.SDK.Analyzers package to your extension project.

I hope this will give you a better starting point for writing extensions. If I forgot to mention something, please let me know in the comments.

Having great samples to help you learn about any programming language or paradigm can be very valuable. In my opinion, a good sample can be characterized by:

Being easy to replicate

Having clear steps that guide the reader to replicating the behavior of the sample into their own code base is paramount. Without clear guidance and explanation on how to consume the sample, the sample is much less efficient and may lead to the reader becoming annoyed.

Being self-contained

The sample needs to contain the needed documentation, code comments and simplicity that makes it easy to understand. It must keep the concept count to a minimum to reduce noise.

Linking to additional resources

A sample is not a replacement for full documentation but shows how to implement concepts that can pan multiple sets of documentation. If the reader is interested in knowing more details about the various technologies and concepts used by the sample, links must be made available.

Being able to build and run

It should be possible to clone the sample to your machine, open it in Visual Studio and being able to run and debug effortlessly. Setting breakpoints and inspecting the code is a fantastic way to help understand how the sample works.

New samples

The Visual Studio extensibility team has a notable set of samples for various different aspects of writing extensions. However, they do not adhere to the rules outlined above and we are looking into updating them accordingly and adding new ones as well.

So, we’ve created some experimental samples on GitHub that addresses some pain points we’ve noticed over the years. They are:

  1. Doing options the right way - This sample shows how to correctly specify and consume options for a Visual Studio extension that is both thread-safe and performant.
  2. VisibilityConstraints - This sample shows how to use the <VisibilityConstraints> element in a Visual Studio extension to remove the need to use the ProvideAutoload attribute on a package class.
  3. Protocol Handlers - This sample shows how to associate a URI protocol with Visual Studio and handle the passed in URI. For instance, a link with a custom protocol (such as vsph://anything/I/want) will open Visual Studio and pass the URI to the extension.
  4. Textmate Grammar - This is a sample project that demonstrates how to ship Textmate grammars inside Visual Studio extensions.

Give us feedback

Please help give us feedback on these new types of samples by either commenting on this blog post or, even better, opening issues directly on the samples on GitHub. The more feedback we get, the better the samples get, and we can start writing lots more of them.

Also, what scenarios should the next batch of Visual Studio extensibility samples address?