Inventor Add-In using C++/CLR

By Adam Nagy

Philippe already created a sample mixed-managed (C++/CLR) add-in that you can have a look at. But I thought it could be useful to list the steps to achieve that. Instead of creating a C++ Inventor add-in using the Inventor Add-In wizard, adding .NET support to it, and separating the generated code from the managed parts using #pragma unmanaged /#pragma managed blocks, it's easier to create a C++/CLR Class Library and implement your ApplicationAddInServer in .NET.

1) Create the "C++/CLR Class Library" - preferably inside "%APPDATA%\Autodesk\ApplicationPlugins" to make your life easier

2) Create a "x64" platform for the project and keep that active

Inside the "Configuration Manager" dialog, under "Active solution platform" select "<New...>" and add the "x64" platform

3) Reference "Autodesk.Inventor.Interop.dll"

Click "PROJECT" >> "References..." and browse to "<Inventor install folder>\Bin\Public Assemblies" and add "Autodesk.Inventor.Interop.dll"

4) Inside the same dialog box also add a reference to "System.Windows.Forms" just so that we can show a message box from our code later on

5) Implement the "ApplicationAddInServer" class

// MyClrAddIn.h

#pragma once

using namespace System;
using namespace System::Runtime::InteropServices;
using namespace System::Windows::Forms;
using namespace Inventor;

namespace MyClrAddIn {
  public ref class StandardAddInServer : public ApplicationAddInServer
  {
  public:
    StandardAddInServer(void)
    {

    }

    virtual void Activate(ApplicationAddInSite^ addInSiteObject, bool firstTime)
    {
      MessageBox::Show("Add-In Loading");
    }

    virtual void Deactivate()
    {
      MessageBox::Show("Add-In Unloading");
    }

    virtual void ExecuteCommand(int CommandID)
    {
    }

    virtual property Object^ Automation
    {
      // If you want to return an interface to another client of this addin,
      // implement that interface in a class and return that class object
      // through this property
      Object^ get()
      {
        return nullptr;
      }
    }
  };
}

5) Create a GUID and a ProgId for the class and make it ComVisible

namespace MyClrAddIn {
  [
    ProgId("MyClrAddIn.StandardAddInServer"),
    GuidAttribute("3543165F-7F19-4614-8842-572A5EBE9549"),
    ComVisible(true)
  ]
  public ref class StandardAddInServer : public ApplicationAddInServer
  {
    // etc...

Note: you can use Visual Studio's "Create GUID" dialog for creating a new GUID

7) Create an *.addin file inside your solution's folder with name "" and content  

<?xml version="1.0" encoding="utf-8"?>
  <!-- Type attribute is same as Type registry key
  (Standard, Translator, Plugin (Server only) -->
  <Addin Type="Standard">
     
  <!-- Should be the same as the "GuidAttribute" in MyClrAddIn.h -->
  <ClassId>{3543165F-7F19-4614-8842-572A5EBE9549}</ClassId>
  <ClientId>{3543165F-7F19-4614-8842-572A5EBE9549}</ClientId>

  <!-- Both of the following fields should be translated.
  NO OTHER FIELDS SHOULD BE TRANSLATED! -->
  <DisplayName>MyClrAddIn</DisplayName>
  <Description>MyClrAddIn</Description>

  <!-- Assumes that MyClrAddIn.dll is in the same folder as the *.addin file -->
  <Assembly>MyClrAddIn.dll</Assembly>

  <SupportedSoftwareVersionGreaterThan>17..</SupportedSoftwareVersionGreaterThan>
  <LoadOnStartUp>1</LoadOnStartUp>
  <Hidden>0</Hidden>
</Addin>

Here is the source code of the project:
https://github.com/adamenagy/Inventor-AddInWithCLR