Lesson 3 – Grouping Components and Controlling Visibility with Attributes

In this lesson, you will extend the Add-In created in Lesson 2 by introducing component grouping using attributes and adding a second command that toggles the visibility of all components in a group.

This lesson demonstrates how to:

• Persist metadata on component occurrences
• Retrieve objects using the AttributeManager
• Control multiple components with a single command
• Design more scalable and maintainable Inventor Add-Ins

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Lesson Objective

In this lesson, you will learn how to:

• Store custom metadata on ComponentOccurrence objects using attributes
• Create multiple ribbon buttons in a single panel
• Use AttributeManager.FindObjects to retrieve grouped components
• Toggle visibility of components programmatically
• Implement multi-command Add-In patterns
• Follow Inventor Add-In lifecycle and cleanup best practices

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Prerequisites

Before starting this lesson, ensure that you meet the following requirements:

Completed Lessons

You should have completed:

• Lesson 1: Creating and Registering an Add-In
• Lesson 2: Adding a Button and Hiding a Component

Required Knowledge

You should be familiar with:

• C# and Visual Studio 2022
• Inventor assemblies and component occurrences
• Ribbon UI customization

Software Requirement

Autodesk Inventor installed and running

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Lesson Description

This lesson introduces the concept of logical grouping of components using Inventor Attributes.

Instead of operating solely on the current selection, the Add-In enables users to:

• Add selected components to a named group
• Hide or show all components belonging to that group with a single click

This approach is widely used in:

• Automation and rule-based modeling
• Assembly management tools
• Visualization workflows

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Step 1 – Add-In Server Class

As in previous lessons, the Add-In implements the ApplicationAddInServer interface.

public class StandardAddInServer : Inventor.ApplicationAddInServer

This class remains the primary entry point for:
• UI creation
• Command registration
• Event handling
• API access

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Step 2 – Add-In Identification (GUID)

[Guid("435f2d68-c329-4b1a-b6cc-fb95aeb479b4")]

Each Add-In requires a unique GUID that:
• Identifies the Add-In in the Windows Registry
• Must match the registry entry
• Should never be changed after deployment

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Step 3 – Storing the Inventor Application Object

private Inventor.Application m_inventorApplication;

The Inventor Application object is:
• Provided during activation
• Stored for later use
• The gateway to all Inventor API functionality

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Step 4 – Activating the Add-In

public void Activate(ApplicationAddInSite addInSiteObject, bool firstTime)

During activation, the Add-In:

• Stores the Inventor application reference
• Loads button icons
• Creates two command definitions
• Registers execution handlers
• Creates the UI (first-time only)

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Step 5 – Creating Multiple Button Definitions

This lesson introduces two buttons:

Button 1 – Add To Group

Adds selected components to a logical group using attributes.

button1Def = m_inventorApplication.CommandManager
    .ControlDefinitions.AddButtonDefinition(
        "Add To Group",
        "AddToGroupButtonName",
        CommandTypesEnum.kNonShapeEditCmdType,
        button1_client_ID,
        "Button to add the Component to a group",
        "Add component to group",
        smallPicture1,
        largePicture1);

Button 2 – Hide or Show Group

Toggles visibility of all components belonging to the group.

button2Def = m_inventorApplication.CommandManager
    .ControlDefinitions.AddButtonDefinition(
        "Hide or Show Group",
        "HideOrShowGroupButtonName",
        CommandTypesEnum.kNonShapeEditCmdType,
        button2_client_ID,
        "Button to hide or show the group",
        "Hide or show the group",
        smallPicture2,
        largePicture2);

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Step 6 – Creating the Ribbon User Interface

The UI is added only to the Assembly environment.

Ribbon ribbon = m_inventorApplication.UserInterfaceManager.Ribbons["Assembly"];

The Add-In:
• Reuses the existing tab if found
• Creates a new tab if necessary
• Adds a Lesson 3 panel
• Places both buttons on the panel

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Step 7 – Adding the Ribbon Tab and Panel

ribbonTab = ribbon.RibbonTabs.Add(
    "MyFirstPlugin",
    "AssemblyDocTab",
    tab_client_ID);

A panel named Lesson 3 is then added, and both buttons are placed inside it.

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Step 8 – Adding Components to a Group (Attributes)

When Add To Group is clicked:

Execution Flow:

Validate user selection

Loop through selected components

Access AttributeSets on each occurrence

Add a named attribute set and value

AttributeSet attbSet = attbSets.Add("myPartGroup");

attbSet.Add("PartGroup1", ValueTypeEnum.kStringType, "Group1");

Attributes act as persistent metadata stored directly on the component occurrence.

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Step 9 – Finding Grouped Components

When Hide or Show Group is clicked, the Add-In uses:

AttributeManager attbMan = asmDoc.AttributeManager;

ObjectCollection objsCol =
    attbMan.FindObjects("myPartGroup", "PartGroup1", "Group1");

This allows the Add-In to retrieve all components that belong to the group—without relying on selection.

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Step 10 – Toggling Component Visibility

Each retrieved object is cast to a ComponentOccurrence, and visibility is toggled:

compOcc.Visible = false;

This provides a clean and efficient way to control multiple components with a single command.

Download the sample assembly file to test this lesson here

Complete source code in both C# and VB.NET is provided and can be downloaded here.

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Lesson Summary

In this lesson, you learned how to:

✅ Group components using Inventor attributes
✅ Retrieve objects using AttributeManager
✅ Add multiple commands to a ribbon panel
✅ Toggle visibility for grouped components
✅ Build scalable, metadata-driven Add-Ins