XmlWriter Class

using System;
using System.Collections.Generic;
using System.Text;
//Include the NameSpace to access the XmlWriter Class
using System.Xml;
using System.Data.SqlClient;
class Program
{

 static void Main()
 {
 //Creating XmlWriter Settings
 XmlWriterSettings settings = new XmlWriterSettings();
 settings.Indent = true;
 settings.IndentChars = "  ";
 settings.NewLineOnAttributes = true;

//Using XmlWriter to create xml file.
 using (XmlWriter writer = XmlWriter.Create("c:\\OrderDetails.xml",settings))
 {
  writer.WriteComment("Order Details of PowerToYou");
  writer.WriteStartElement("OrderDetails");
  writer.WriteStartElement("Order");
  writer.WriteAttributeString("OrderID","O001");
  writer.WriteElementString("ProductName","ASP.NET2.0");
  writer.WriteElementString("Price","0");
  writer.WriteEndElement();
  writer.WriteStartElement("Order");
  writer.WriteAttributeString("OrderID","O002");
  writer.WriteElementString("ProductName","Mono-Develop-SDK");
  writer.WriteElementString("Price","0");
  writer.WriteEndElement();
  writer.WriteEndElement();
  writer.Flush();
  
 }
 
 
  
 }
 
}




Result: Xml file in c:\OrderDetails.xml



<?xml version="1.0" encoding="utf-8"?>
<!--Order Details of PowerToYou-->
<OrderDetails>
  <Order
    OrderID="O001">
    <ProductName>ASP.NET2.0</ProductName>
    <Price>0</Price>
  </Order>
  <Order
    OrderID="O002">
    <ProductName>Mono-Develop-SDK</ProductName>
    <Price>0</Price>
  </Order>
</OrderDetails>

Following will put indented xml into s variable.

static void Main(string[] args)
{
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.LoadXml("<book><page></page></book>"); // unindented xml
using (MemoryStream ms = new MemoryStream())
{
XmlWriterSettings xws = new XmlWriterSettings();
xws.Indent = true;
using (XmlWriter xmlWriter = XmlWriter.Create(ms, xws))
{
xmlDocument.WriteTo(xmlWriter);
}
ms.Position = 0; StreamReader sr = new StreamReader(ms);
string s = sr.ReadToEnd(); // s will contain indented xml
Console.WriteLine(s);
}
}