Visual Studio - Writing a simple Add-In (plugin)

An add-in is an extension which integrates with the Visual Studio environment and provides new functionality to it. An add-in has full access to Visual Studio (IDE) tools and APIs and can interact with them. An add-in is a compiled DLL file which can be loaded by Visual Studio when it starts.





Creating a Sample Add-In
1. Create a New → Project
2. Select Other Project Types → Extensibility → Visual Studio Add-in



3. An Add-In wizard pops up which will guide you through a series of 7 steps including the welcome page to configure your add-in









Select for creating a 'Tools' menu item. This will list the add-in in tools menu items







On clicking finish, three main files are generated for you
a) CommandBar.resx (Resource File)
b) Connect.cs (Main class file for Add-In logic)
c) WizardSample.AddIn (XML Configuration file for your add-in)


Build the solution and run the project. You will see a Visual Studio instance running within the visual studio. Click on 'Tools' and you can find your Add-In there.




Modify the function OnConnection() as below to add the plugin to 'MenuBar'

public void OnConnection(object application, ext_ConnectMode connectMode,
        object addInInst, ref Array custom)
{

    _applicationObject = (DTE2)application;
    _addInInstance = (AddIn)addInInst;
    if(connectMode == ext_ConnectMode.ext_cm_UISetup)
    {
        object []contextGUIDS = new object[] { };
        Commands2 commands = (Commands2)_applicationObject.Commands;
        CommandBar bar = ((CommandBars)_applicationObject.CommandBars)["MenuBar"];

        try{
            Command command = commands.AddNamedCommand2(
                    _addInInstance, "MyAddin1", "Demo", "Do Something", true, 59,
                    ref contextGUIDS,(int)vsCommandStatus.vsCommandStatusSupported+
                    (int)vsCommandStatus.vsCommandStatusEnabled,
                    (int)vsCommandStyle.vsCommandStylePictAndText,
                    vsCommandControlType.vsCommandControlTypeButton);

            //Add a control for the command to the tools menu:

            if(command != null) {
                command.AddControl(bar, 1);
            }
        }
        catch(System.ArgumentException){
        }
    }
}

Modify Exec() function to add some functionality to the plugin

public void Exec(string commandName, vsCommandExecOption executeOption,
        ref object varIn, ref object varOut, ref bool handled)
{
    handled = false;
    if(executeOption == vsCommandExecOption.vsCommandExecOptionDoDefault)
    {
        if(commandName == "MyAddin1.Connect.MyAddin1")
        {
            handled = true;
            MessageBox.Show("Hello from Demo AddIn");

            return;
        }
    }
}