How to convert the datatable to xml format

I have done this for dataset.You can try it for DataTable

XmlSerializer tXmlSerializer = new XmlSerializer(tDataSet.GetType());
System.IO.MemoryStream tStream = new System.IO.MemoryStream();
tDataSet.DataSetName = "ITEM";
tDataSet.Tables[0].TableName = "MST_ITEM";
tDataSet.WriteXml(tStream);
String tSerilaizedObject = System.Text.Encoding.UTF8.GetString(tStream.ToArray());

tSerilaizedObject should contain the xml

How to import /export database data from /to csv/XML/excel using ASP.NET and C#.

for complate example visit: http://dotnetawesome.blogspot.com/2013/11/how-to-import-export-database-data-from_16.html

protected void btnExport_Click(object sender, EventArgs e)
        {
            using (MuDatabaseEntities dc = new MuDatabaseEntities())
            {
                List<EmployeeMaster> emList = dc.EmployeeMasters.ToList();
                if (emList.Count > 0)
                {
                    var xEle = new XElement("Employees",
                        from emp in emList
                        select new XElement("Employee",
                            new XElement("EmployeeID", emp.EmployeeID),
                            new XElement("CompanyName", emp.CompanyName),
                            new XElement("ContactName", emp.ContactName),
                            new XElement("ContactTitle", emp.ContactTitle),
                            new XElement("EmployeeAddress", emp.EmployeeAddress),
                            new XElement("PostalCode", emp.PostalCode)
                            ));
                    HttpContext context = HttpContext.Current;
                    context.Response.Write(xEle);
                    context.Response.ContentType = "application/xml";
                    context.Response.AppendHeader("Content-Disposition", "attachment; filename=EmployeeData.xml");
                    context.Response.End();
                }
            }
        }

CODE FOR YOUR SOLUTION



DataTable dtdt = (DataTable)Grid_Name.DataSource;

//or

//(data table came from database)



dtdt.TableName = "MySampleTable";


MemoryStream mstr = new MemoryStream();
dt.WriteXml(mstr, true);
mstr.Seek(0, SeekOrigin.Begin);
StreamReader sr = new StreamReader(mstr);
string xmlString;
xmlString = sr.ReadToEnd();
return (xmlString);