//这个控件应该在aspx文件中定义.
            FileUpload fu1 = new FileUpload();
            string path = @"d:\a.xls";
            fu1.PostedFile.SaveAs(path);
            string connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path +
            ";Extended Properties='Excel 8.0;HDR=yes;IMEX=1;'";
            string selectCommand = " SELECT * FROM [Sheet1$] ";
            DataTable dt = new DataTable();
            using (var conn = new System.Data.OleDb.OleDbConnection(connString))
            {
                var adt = new System.Data.OleDb.OleDbDataAdapter(selectCommand, conn);
                adt.Fill(dt);
            }

            var root = new XElement("ImportFromExcel");
            var lstHeader=new List<string>();
            foreach (DataColumn dc in dt.Columns)
                lstHeader.Add(dc.ColumnName);
            var data = new XElement("Data");
            XElement row;
            foreach(DataRow dr in dt.Rows)
            {
                row = new XElement("add");
                for (int i = 0; i < lstHeader.Count; i++)
                    row.Add(new XAttribute(lstHeader[i], dr[i].ToString()));
                data.Add(row);
            }
            root.Add(data);
            root.Save(@"d:\a.xml");