Calculate total for each row in gridview

Step 1: Declare a page scope variable double dbltotal=0; Step 2: In GridView1_RowDataBound event, find the price and quantity field. then if (e.Row.RowType == DataControlRowType.DataRow) { double price = (write code to find price column); double quantity=(write code to find quantity column); dbltotal+=(Convert.ToDouble(price)*Convert.ToDouble(quantity)); } if (e.Row.RowType == DataControlRowType.Footer) { e.Row.Cells[Your Column Number where you want to show Grand Total].Text = dbltotal; }

I have used this same logic but i am not getting the desired result