Creating and registering a COM component that can be used in NAV

We will implement a simple custom COM component that exposes an interface to multiply two decimal numbers.

How to do it...

1. Start Visual Studio and create a new project. The initial steps repeat those from the Developing your own .NET class recipe from Chapter 4, .NET Interoperability in C/AL - you need to create a project based on a Class Library template. Name the project NAVAutomationServer and choose to create a new solution for the project.

2. In the new project, remove all automatically generated using directives and insert one instead:

           using System.Runtime.InteropServices; 
   

3. The following is code of the exported class:

           namespace NavAutomationServer 
           { 
             [ComVisible(true)] 
             public interface IMultiplication 
             { 
               int Multiply(int x, int y); 
             } 
    
    
             [ComVisible(true)] 
             [ProgId("My.TestClass")] 
             public class Multiplication : IMultiplication...