private void cargarCbx()
 {
     this.cbxInventarios.DataSource = controller.llenarCbx();
 }
 private void actualizarCbx()
 {
     this.cbxProductos.DataSource  = controller.llenarCbx();
     this.cbxUpdateProd.DataSource = controller.llenarCbx();
     this.cbxEliminar.DataSource   = controller.llenarCbx();
 }