private void OnItemTapped(object sender, ItemTappedEventArgs e)
{
voceMenu tappedItem = e.Item as voceMenu;
cambiaPagina(tappedItem.Comando);
}
private void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
{
voceMenu selectedItem = e.SelectedItem as voceMenu;
cambiaPagina(selectedItem.Comando);
}