Chaining an XmlReader to an XmlWriter : XmlReader « XML « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. XML
3. XmlReader

using System;
using System.Xml; 
using System.IO;
using System.Text;
public class Test2{
  static string ipKey;
  static string httpMethodKey;
  static string fileKey; 
  static string dateKey;
  static string referrerKey; 

  public static void WriteAttributes(XmlReader reader, XmlWriter writer){
    
    if(reader.MoveToFirstAttribute()){
      do{
        writer.WriteAttributeString(reader.Prefix, 
                reader.LocalName, 
                reader.NamespaceURI,
                reader.Value); 
      }while(reader.MoveToNextAttribute());
      reader.MoveToElement(); 
    }
  }

  public static void WriteEvent(XmlWriter writer, string ip){
    
    writer.WriteStartElement("event"); 
    writer.WriteElementString("ip", ip);
    writer.WriteEndElement(); 
  } 

  public static void ReadEvent(XmlReader reader, out string ip){

    ip = null; 

    while( reader.Read() && reader.NodeType != XmlNodeType.EndElement){                
      
 if (reader.NodeType == XmlNodeType.Element) {
          
     if(reader.Name == ipKey){   
       ip = reader.ReadString(); 
     }
    }//while   
  }
  }
  public static void Main(string[] args){
    string ip; 
    XmlNameTable xnt = new NameTable(); 
    ipKey            = xnt.Add("ip"); 
    
    //load XmlTextReader using XmlNameTable above 
    XmlTextReader xr = new XmlTextReader("logfile.xml", xnt);
    xr.WhitespaceHandling = WhitespaceHandling.Significant;

    XmlValidatingReader vr = new XmlValidatingReader(xr);
    vr.ValidationType = ValidationType.None;
    vr.EntityHandling = EntityHandling.ExpandEntities; 


    StreamWriter sw =  new StreamWriter ("logfile-archive.xml", false, Encoding.UTF8 ); 
    XmlWriter xw    = new XmlTextWriter (sw);                 
    
    vr.MoveToContent();
    xw.WriteStartElement(vr.Prefix, vr.LocalName, vr.NamespaceURI);
    WriteAttributes(vr, xw);    
     
    vr.Read(); 
    do
    {
      ReadEvent(vr, out ip);
      WriteEvent(xw,ip); 
      vr.Read(); 
    } while(vr.NodeType == XmlNodeType.Element);
     
   
    vr.Close();
    xw.Close();
  }
}