public SaleListItemViewModel AddGoods(int goodsID, SaleListViewModel saleList, ObservableCollection <SaleListItemViewModel> salelistItems) { var goods = localDBDao.GetGoods(goodsID); int newSeqID = 1; if (salelistItems.Count > 0) { newSeqID = salelistItems.Max(x => x.SeqID) + 1; } var newItem = new SaleListItemViewModel { SheetID = saleList.SheetID, SeqID = newSeqID, GoodsID = goodsID, GoodsName = goods.Rows[0]["shortname"].ToString(), BarcodeID = goods.Rows[0]["barcodeid"].ToString(), Quantity = 1, SalePrice = Convert.ToDecimal(goods.Rows[0]["Price"]), SaleValue = Convert.ToDecimal(goods.Rows[0]["Price"]) * 1, Cost = Convert.ToDecimal(goods.Rows[0]["cost"]) }; salelistItems.Add(newItem); this.UpdateSalesData(saleList, salelistItems); salesDBDao.AddSaleListItem(newItem.SheetID.ToString(), newItem.SeqID, newItem.GoodsID, newItem.GoodsName, newItem.BarcodeID, newItem.Quantity, newItem.Cost, newItem.SalePrice, newItem.SaleValue, newItem.DiscValue); return(newItem); }