private void button_Afficher_Click(object sender, EventArgs e)
        {
            listView1.Items.Clear();
            Employes        emp     = new Employes();
            List <Employes> listEmp = emp.ListeEmployee();

            foreach (Employes em in listEmp)
            {
                ListViewItem item = new ListViewItem(em.NoIdentifiant.ToString());
                item.SubItems.Add(em.MPasse);
                item.SubItems.Add(em.NomUtil);
                item.SubItems.Add(em.PrenomAdmin);
                item.SubItems.Add(em.Categorie);

                listView1.Items.Add(item);
            }
        }