Creating a Visual Studio Extension

29 May 2013 17:21

The next major piece is the Visual Studio extension, so let’s get on with that. Assuming that you’ve installed the Visual Studio 2012 SDK, it’s as simple as creating a new “Visual Studio Package” (it’s under “Visual C#” / “Extensibility”):

  1. Choose ‘C#’ as the language.
  2. Generate a new SNK file, rather than use an existing one.
  3. Fill in the basic package information (name, etc.). Use the default icon.
  4. We’ll need a menu command. Name it “View Welcome Page” and give it the ID “cmdidViewWelcomePage”.
  5. Don’t bother with unit or integration tests. We’ve only got a weekend, this is a spike, and there’s going to be almost no code in here anyway.

Fire it up; you’ll get a new (experimental) instance of Visual Studio, and our extension adds a menu item to the top of the Tools menu.

Moving the menu item

We want our menu item to be in the View menu, so we’ll have to move it. Open the StartPage.vsct file and change IDM_VS_MENU_TOOLS to IDM_VS_MENU_VIEW. Build the project and check that it’s moved.

Hooking solution open events

To hook the solution open events, we need to subscribe to the ISolutionEvents interface in Visual Studio. Before we can do that, however, we need to tell Visual Studio to load our extension early enough.

To do this, we need to add the ProvideAutoLoad attribute to our package class:

// We need to load early enough to be able to hook solution events.
// VSConstants.UICONTEXT_NoSolution

Then we need to hook the solution events. We can do this inside Initialize. Refer to the source code on github for complete details, but it’s basically the following:

_solution = GetService(typeof (SVsSolution)) as IVsSolution;
if (_solution != null)
    _solution.AdviseSolutionEvents(this, out _dwCookie);

Then we make our package implement ISolutionEvents, returning VSConstants.S_OK from everything except OnAfterOpenSolution, which is where we want to add our functionality.