public bool AddItems(int userId, ItemDataBase[] items) { if (!_carts.TryGetValue(userId, out var dbItems)) { _carts[userId] = new List <ItemDataBase>(items); return(true); } foreach (var item in items) { var search = new ItemSearch(item.Id); var ind = dbItems.FindIndex(search.HasId); if (ind < 0) { dbItems.Add(item); } else { dbItems[ind].Quentity += item.Quentity; } } return(true); }