How To Create Object Wrappers

Question

Hi there,
I would like to implement some better and custom error handling in some of the business objects.  Objects such as the Recordset and Documents can have a tendency to 'die' on a line that errors and I would like to create wrappers for these classes so I can handle them using common methods.
I have tried to create new classes inheriting from RecordsetClass and DocumentsClass and everything compiles fine but produces COM errors as soon as I try to access them at runtime.  Are we just out of luck trying to enhance these classes?  Is our only option to write a one-off wrapper that simply handles the SBO object type internally in our new class?
It would seem very beneficial to be able to extend these objects in order to implement common methods and business rules.  Has anyone been successful at doing this?
Here is my class declaration that fails when I try to access it at runtime:
using System;
using System.Runtime.InteropServices;
using SAPbobsCOM;
namespace NMO.SAP.Shared
    /// <summary>
    /// PLS Wrapper for the SAP Documents object
    /// </summary>
    public class SBODocuments : DocumentsClass
        private SAPbobsCOM.Company sboCompany;
        public SBODocuments(SAPbobsCOM.Company company)
            this.sboCompany = company;
        /// <summary>
        /// New implementation of the Add method returning true or false
        /// </summary>
        /// <returns>True or false</returns>
        public new Boolean Add()
            Boolean retVal = true;
            try
                // Add method returns 0 if successful
                if (base.Add() != 0)
                    retVal = false;
                    SBOErrorHandler.HandleSAPError(this.sboCompany);
            catch (COMException cex)
                retVal = false;
                SBOErrorHandler.HandleSAPError(this.sboCompany, cex);
            catch (Exception ex)
                retVal = false;
                SBOErrorHandler.HandleSAPError(this.sboCompany, ex);
            return retVal;
Thanks very much,
David

Answer 1

David,
A good aproach would be to convert .COM objects to .NET
This application <a href="http://www.aurigma.com/Products/COMtoNET/">COMtoNET</a>
Will generate all the C# Code needed to convert COM objects to .NET, and then you'll be able to catch any event, error and so on.