datagridview导入导出xml

using System.IO;   

#region   导入到XML

        private void btnLeadInToXml_Click(object sender, EventArgs e)
        {

            this.openFileDialog1.Filter = "XML文件（*.xml）|*.xml";
            if (this.openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                string filename = this.openFileDialog1.FileName;
                DataSet ds = new DataSet();
                ds.ReadXml(filename);
                this.dgvDictionary.DataSource = ds.Tables[0];

            }


        }
        #endregion


        #region   文件导出到XML文件

        private void btnExportToXml_Click(object sender, EventArgs e)
        {
            this.saveFileDialog1.FileName = DateTime.Now.ToString("yyMMddhhmmss");
            this.saveFileDialog1.Filter = "XML文件(*.xml)|*.xml";
            if (this.saveFileDialog1.ShowDialog() == DialogResult.OK)
            {