public bool AddFavourite(int id) { string username = DBHandler.GetTempUsername(this); bool check = DBHandler.GetFavourites().Exists(x => x.LocationId.Equals(id) && x.Username.Equals(username)); if (check) { Favourite oldFavourite = DBHandler.GetFavourites().FirstOrDefault((x => x.LocationId.Equals(id) && x.Username.Equals(username))); DBHandler.RemoveFavourite(oldFavourite); return(false); } else { Favourite newFavourite = new Favourite { LocationId = id, Username = username }; DBHandler.AddFavourite(newFavourite); return(true); } }