protected void PrintFinded_Click(object sender, EventArgs e) { List <int> allCards = (List <int>)Session["cardsIds"]; if (allCards == null) { return; } List <PrintManyParams> printParams = new List <PrintManyParams>(); foreach (int cardId in allCards) { CollectedCards card = main.GetCardById(cardId); printParams.Add(new PrintManyParams() { CardId = cardId, RegisterId = card.FkRegister, Version = main.GetLastVersionByCard(cardId) }); } Session["PrintManyParams"] = printParams; Response.Redirect("PrintMany.aspx"); }