public void OnPopupUnitsCallbackVarios(object sender, EventArgs e)
        {
            try
            {
                var x   = sender as PopupVarios;
                var iva = x.iva;
                if (iva != null)
                {
                    txtTantoPorcierto.Text = iva.Porcentaje.ToString();
                    RepositorySatApp database = new RepositorySatApp();
                    var nuevoIva = database.ObtenerRecargoIva(iva.Codigo);

                    nuevaLinea.Recargo = nuevoIva.Recargo;
                    nuevaLinea.Iva     = iva.Porcentaje;

                    database.CerrarConexion();
                }
                else
                {
                    Application.Current.MainPage.DisplayAlert("Aviso", "Forma de Pago incorrecta.", "OK");
                }
            }
            catch (Exception ex)
            {
                Application.Current.MainPage.DisplayAlert("Aviso ", ex.Message, " OK");
            }
        }