Write your own GetXml function

The DataSet object in .NET has a GetXml function. The method takes data from all the tables and from all rows and creates XML. The problem is that you cannot change this XML. So I created a method that does something similar:

private string GetXmlFromDataset(DataSet dataSet, bool isStatefull) {
    XmlTextWriter xwriter = null;
    try
    {
        xwriter = new XmlTextWriter(new MemoryStream(), Encoding.UTF8);
        xwriter.WriteStartElement("NewDataSet");
        //start enumerate in table collection
        foreach (DataTable dt in dataSet .Tables )
        {
            int rowNum = 0;
            DateTime tmp = DateTime.MinValue;
            if (isStatefull)
                dt.Columns.Add(new DataColumn("IsDummy", typeof(bool)));
            if (isStatefull && dt.Rows.Count == 0)
            {
                dt.Rows.Add(dt.NewRow());
                dt.Rows[0]["IsDummy"] = true;
            }
            //start enumerate in rows collection
            foreach (DataRow dr in dt.Rows)
            {
                //start <table> element
                xwriter.WriteStartElement(dt.TableName);
                if (isStatefull)
                {
                    xwriter.WriteAttributeString("stat", "0");
                    xwriter.WriteAttributeString("rowNum", rowNum.ToString());
                }
                DateTime tmpDate = DateTime.MinValue  ;
                //start enumerate in columns collection
                foreach (DataColumn dc in dr.Table.Columns)
                {
                    string colValue = String.Empty;
                    switch (dc.DataType.Name)
                    {
                        case "DateTime":
                            if (DateTime.TryParse(dr[dc, 
                                     DataRowVersion.Current].ToString(), 
                                     out tmpDate))
                                colValue = tmpDate.ToString("yyyy-MM-ddTHH:mm:ss");
                            else 
                                colValue = dr[dc, DataRowVersion.Current].ToString();
                            break;
                        default:
                            colValue = dr[dc, DataRowVersion.Current].ToString();
                            break;
                    }
                    xwriter.WriteStartElement(dc.ColumnName.Replace(" ","_x0020_"));
                    if ( isStatefull || String.Compare(
                           dc.DataType.Name, "string", true) != 0)
                    {
                        xwriter.WriteAttributeString("datatype", dc.DataType.Name);
                    }
                    if (isStatefull)
                    {
                        xwriter.WriteAttributeString("stat", "0");
                    }
                    xwriter.WriteString(colValue);
                    xwriter.WriteEndElement();
                }
                //end <table> element
                xwriter.WriteEndElement();
                rowNum++;
            }
        }
        //end <newdataset> element
        xwriter.WriteEndElement();
        xwriter.Flush();
        xwriter.BaseStream.Seek(0, SeekOrigin.Begin);
        StreamReader reader = new StreamReader(xwriter.BaseStream);
        return reader.ReadToEnd();
    }
    finally
    {
        if (xwriter != null)
        {
            xwriter.Close();
            xwriter = null;
        }
    }
}

You can read about in my blog: http://gregnozik.blogspot.com/2011/09/getxml-dataset-method-not-good-enough.html.