XmlSerializer.Deserialize Method (TextReader)

using System;
using System.IO;
using System.Text;
using System.Xml.Serialization;

// This is the class that will be deserialized. 
public class OrderedItem
{
    [XmlElement(Namespace = "http://www.cpandl.com")]
    public string ItemName;
    [XmlElement(Namespace = "http://www.cpandl.com")]
    public string Description;
    [XmlElement(Namespace = "http://www.cohowinery.com")]
    public decimal UnitPrice;
    [XmlElement(Namespace = "http://www.cpandl.com")]
    public int Quantity;
    [XmlElement(Namespace = "http://www.cohowinery.com")]
    public decimal LineTotal;
    // A custom method used to calculate price per item. 
    public void Calculate()
    {
        LineTotal = UnitPrice * Quantity;
    }
}

public class Test
{
   public static void Main()
   {
      Test t = new Test();
      // Read a purchase order.
      t.DeserializeObject("simple.xml");
   }
   private void DeserializeObject(string filename)
   {   
      Console.WriteLine("Reading with TextReader");

      // Create an instance of the XmlSerializer specifying type.
      XmlSerializer serializer = 
      new XmlSerializer(typeof(OrderedItem));

      // Create a TextReader to read the file. 
      FileStream fs = new FileStream(filename, FileMode.OpenOrCreate);
      TextReader reader = new StreamReader(fs);

      // Declare an object variable of the type to be deserialized.
      OrderedItem i;

      // Use the Deserialize method to restore the object's state.
      i = (OrderedItem) serializer.Deserialize(reader);

      // Write out the properties of the object.
      Console.Write(
      i.ItemName + "\t" +
      i.Description + "\t" +
      i.UnitPrice + "\t" +
      i.Quantity + "\t" +
      i.LineTotal);
   }
}