How to Get GridView Header Name With Cell Values and Convert to XML

sb.Append("<Results>");
            foreach (GridViewRow item in GridView1.Rows)
            {
                if (item.RowType == DataControlRowType.DataRow)
                {
                    for (int i = 0; i < item.Cells.Count; i++)
                    {
                        sb.Append("<" + GridView1.HeaderRow.Cells[i].Text + ">" + item.Cells[i].Text + "</" + GridView1.HeaderRow.Cells[i].Text + ">");
                    }
                }
            }
            sb.Append("</Results>");