private void TextBoxCodigoBarras_Pasting(object sender, DataObjectPastingEventArgs e)
 {
     if (e.DataObject.GetDataPresent(typeof(string)))
     {
         string entrada = (string)e.DataObject.GetData(typeof(string));
         if (!ServiciosDeValidacion.ValidarEntero(entrada))
         {
             e.CancelCommand();
         }
     }
     else
     {
         e.CancelCommand();
     }
 }