private async Task FillCollectionsAsync() { List <string> list = await DataGetSet.GetGenresAsync(); list.Insert(0, "NA"); _genres = new ObservableCollection <string>(list); list = await DataGetSet.GetCatalogsAsync(); list.Insert(0, "NA"); _catalogs = new ObservableCollection <string>(list); list = await DataGetSet.GetMediaAsync(); list.Insert(0, "NA"); _medias = new ObservableCollection <string>(list); list = new List <string>(); // await DataGetSet.GetInterpretersAsync(); list.Add("NA"); _artists = new ObservableCollection <string>(list); list = new List <string>(); // await DataGetSet.GetAlbumsAsync(); list.Add("NA"); _albums = new ObservableCollection <string>(list); }