DataSet 轉xml

T_GZUNIT u = new T_GZUNIT();

            u.UNITID = 33333;

            u.CANTONID = 4444;

            u.PHASE = "2011-11";

            T_GZUNIT u1 = new T_GZUNIT();

            T_GZUNIT u2 = new T_GZUNIT();

            T_GZUNIT u3 = new T_GZUNIT();

            List<T_GZUNIT> lst = new List<T_GZUNIT>() { u, u1, u2, u3 };

            DataTable dt = DataConvert.ListToDataTable(lst);

            DataSet ds = new DataSet("UNITINFO");

            dt.TableName = "UNIT";

            ds.Tables.Add(dt);

            StringBuilder sb = new StringBuilder();

            string filename = "myXmlDoc.xml ";

            //   Create   the   FileStream   to   write   with.

            System.IO.FileStream myFileStream = new System.IO.FileStream

                  (filename, System.IO.FileMode.Create);

            System.Xml.XmlTextWriter myXmlWriter =

              new System.Xml.XmlTextWriter(myFileStream, System.Text.Encoding.GetEncoding("UTF-8"));

            myXmlWriter.WriteStartDocument();

            ds.WriteXml(myXmlWriter, XmlWriteMode.IgnoreSchema);

  public static DataTable ZeroNullValues(this DataTable dataTable)

        {

            foreach (DataRow row in dataTable.Rows)

            {

                for (int i = 0; i < dataTable.Columns.Count; i++)

                {

                    if (row[i]==System.DBNull.Value)

                    {

                        Type columnType = dataTable.Columns[i].DataType;

                        if (columnType == typeof(string))

                        {

                            row[i] = string.Empty;

                        }

                        else if (columnType == typeof(int) || columnType == typeof(long))

                            row[i] = 0;

                        else if (columnType == typeof(float) || columnType == typeof(double))

                            row[i] = 0.00F;

                    }

                }

            }

            return dataTable;

        }