Based on what you have said, I believe this sql query should pull all the information:
SELECT SUM((rd.ItemSellPrice - rd.ItemBuyPrice) * rd.ItemCount) AS ItemTotalProfit, i.Barcode, i.ItemName, i.ItemSellPrice
FROM ReceiptDetails as rd join Items as i on rd.Barcode = i.Barcode
WHERE (rd.Barcode = ?)
I've assumed that Barcode, ItemName and ItemSellPrice are all fields in the Item table.
You need to extend your dataset to be able to hold these additional fields.
Let me know how that goes for you.