Ajouter une entrée dans le menu contextuel du LinesEditor de la BillingForm

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Windows.Forms;
using MercatorApi;
using MercatorUi;
using System.Data.SqlClient;

namespace Billing
{
    public class Customizer : MercatorUi.ICustomizers.IBillingEngineCreated, MercatorUi.ICustomizers.IBillingEngineClosed
    {

        public void BillingEngineCreated(MercatorUi.Engine.Gescom.BillingEngine BillingEngine)
        {
            BillingEngine.BillingFormLoaded += new EventHandler(BillingEngine_BillingFormLoaded);
        }

        public void BillingEngineClosed(MercatorUi.Engine.Gescom.BillingEngine BillingEngine)
        {
            BillingEngine.BillingFormLoaded -= new EventHandler(BillingEngine_BillingFormLoaded);
        }

        void BillingEngine_BillingFormLoaded(object sender, EventArgs e)
        {
            MercatorUi.Engine.Gescom.BillingEngine billingEngine = (MercatorUi.Engine.Gescom.BillingEngine)sender;
            if (billingEngine.BillingForm.LinesEditor != null)
            {
                billingEngine.BillingForm.LinesEditor.Grid.ContextMenuStripGrid.Items.Add(new ToolStripSeparator());
                ToolStripMenuItem mnuTest = new ToolStripMenuItem("Menu de Test");
                mnuTest.Click += new EventHandler(mnuTest_Click);
                billingEngine.BillingForm.LinesEditor.Grid.ContextMenuStripGrid.Items.Add(mnuTest);
            }
        }

        void mnuTest_Click(object sender, EventArgs e)
        {
            MercatorUi.Forms.Billing.BillingForm billingForm = (MercatorUi.Forms.Billing.BillingForm)MercatorUi.Globals.Main.WonTopForm();
            MercatorUi.Engine.Gescom.BillingEngine billingEngine = billingForm.BillingEngine;
            ...
        }
    }
}