I got Error in this code

protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.DataItem != null)
        {

            DataRowView drv = (DataRowView)e.Row.DataItem;
            string catName = Convert.ToString(drv["CategoryName"]);
            if (catName.Trim() == "Confections")
                e.Row.BackColor = System.Drawing.Color.LightBlue;
        }

    }