public async Task initData()
        {
            OffresList.Clear();
            IEnumerable <OffreM> offres = await OffreS.getInstance().getOffrebyRegion(null, true);

            offres.ToList().ForEach(o =>
            {
                OffresList.Add(o);
            });
        }
        public async Task FilterFavoris(RegionM region)
        {
            OffresList.Clear();
            IEnumerable <OffreM> offres = await OffreS.getInstance().getOffrebyRegion(region, true);

            offres.ToList().ForEach(o =>
            {
                OffresList.Add(o);
            });
        }
 private void ToggleButton_Click(object sender, RoutedEventArgs e)
 {
     OffreS.getInstance().toogleFavorite(ViewModel.offre);
 }