Add Menus and Submenus to Studio Pro Using C#

Last modified: November 14, 2025

Introduction

This how-to describes how to add a menu that contains sub-menus, some of which also contain sub-menus of their own.

You can download the example in this how-to in this GitHub repository.

Prerequisites

This how-to uses the results of Create a Menu Extension Using C#. Complete that how-to before starting this one.

Creating Menu Extension Class

  1. Open the project you created when following Create a Menu Extension Using C#.

  2. Add a new class to the project and name it MyMenuExtension.cs.

  3. Replace the code in the file with the following:

    using Mendix.StudioPro.ExtensionsAPI.UI.Menu;
using Mendix.StudioPro.ExtensionsAPI.UI.Services;
using System.ComponentModel.Composition;

namespace MyCompany.MyProject.MendixExtension;

[Export(typeof(MenuExtension))]
public class MyMenuExtension : MenuExtension
{
    readonly IMessageBoxService messageBoxService;

    [ImportingConstructor]
    public MyMenuExtension(IMessageBoxService messageBoxService)
    {
        this.messageBoxService = messageBoxService;
    }

    public override IEnumerable<MenuViewModel> GetMenus()
    {
        var ristretto = new MenuViewModel("Ristretto", () => messageBoxService.ShowInformation("Ristretto"));
        var regularExpresso = new MenuViewModel("Regular Espresso", () => messageBoxService.ShowInformation("Regular Espresso"));
        var espresso = new MenuViewModel("Espresso", [regularExpresso, ristretto]);
        var blackCoffee = new MenuViewModel("Black Coffee", () => messageBoxService.ShowInformation("Black Coffee"));
        var decaf = new MenuViewModel("Decaf", () => messageBoxService.ShowInformation("Decaf")) { Separator = MenuSeparator.After };
        var coffee = new MenuViewModel("Coffee", [blackCoffee, decaf, espresso]);

        var tea = new MenuViewModel("Tea", () => messageBoxService.ShowInformation("Tea"));

        var hot = new MenuViewModel("Hot", [coffee, tea]);

        var soda = new MenuViewModel("Soda", () => messageBoxService.ShowInformation("Soda"));
        var cold = new MenuViewModel("Cold", [soda]);

        var beverages = new MenuViewModel("Beverages", [hot, cold]);
        yield return beverages;
    }
}

The code above creates a single menu, Beverages. This menu contains the following:

  • Beverages contain two sub-menus: Hot and Cold
  • Hot contains Coffee and Tea
  • Coffee contains Black Coffee, Decaf, and Espresso
  • Espresso contains Regular Espresso and Ristretto
  • Cold contains Soda

Only the top-most parent menu (Beverages) is returned from the GetMenus method. You should only return menus that do not have a parent.

If an app contains one or more extensions, a top-level menu named Extensions will appear in the main menu bar of Studio Pro.

Menus that are created from MenuExtension implementations are grouped by their extension entry point name (in this example, MyCompany), and are placed under a dedicated sub-menu. For example, MyMenuExtension will be placed as follows: Extensions > MyCompany > MyMenuExtension.

A menu can either:

  • Be a parent (a menu that contains sub-menus), or
  • Have an action

You cannot create a menu that both contains sub-menus and has an action.

Separators

You can add a MenuSeparator to a menu using the Separator property. The options include:

  • After
  • Before
  • None (default).

Enabling and Disabling Menus

Menus are enabled by default. To disable a menu, set its IsEnabled property to false.