Export RadGridView to XML

        private void RadForm1_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'nwindDataSet.Customers' table. You can move, or remove it, as needed.
            this.customersTableAdapter.Fill(this.nwindDataSet.Customers);
            this.radGridView1.BestFitColumns();
        }
     
        DataTable dt = new DataTable();

        private void radButton1_Click(object sender, EventArgs e)
        {
            dt = new DataTable();
            foreach (GridViewColumn col in this.radGridView1.Columns)
            {
                dt.Columns.Add(col.Name);
            }
            dt.Columns.Add("Group");

            TraverseRows(this.radGridView1.ChildRows);
            this.radGridView2.DataSource = dt;
            this.radGridView2.BestFitColumns();
        }

        private void TraverseRows(IEnumerable<GridViewRowInfo> rows)
        {
            foreach (GridViewRowInfo row in rows)
            {
                GridViewGroupRowInfo groupRow = row as GridViewGroupRowInfo;
                if (groupRow != null)
                {
                    DataRow addedRow = dt.Rows.Add();
                    addedRow["Group"] = groupRow.HeaderText;
                    TraverseRows(groupRow.ChildRows);
                }
                else
                {
                    DataRow addedRow = dt.Rows.Add();
                    foreach (GridViewCellInfo cell in row.Cells)
                    {
                        addedRow[cell.ColumnInfo.Name] = cell.Value;
                    }
                }

            }
        }