private void btnbuscar_Click(object sender, RoutedEventArgs e)
 {
     Mouse.OverrideCursor = Cursors.Wait;
     if (chkbarra.IsChecked.Value)
     {
         txtarticulo_KeyDown(btnbuscar, new KeyEventArgs(Keyboard.PrimaryDevice, Keyboard.PrimaryDevice.ActiveSource, 0, (Key.Enter)));
     }
     else
     {
         dg2.ItemsSource = Dat_Venta.Datos_art_tallaemp(_liq_id, txtarticulo.Text).DefaultView;
     }
     Mouse.OverrideCursor = null;
 }