File Directory Stream C# Tutorial

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
[Serializable]
class Employee
{
  private int Number;
  private string FirstName;
  private string LastName;
  public void WriteEmployee(){
    Console.WriteLine("Number: " + this.Number);
    Console.WriteLine("FirstName: " + this.FirstName);
    Console.WriteLine("LastName: " + this.LastName);
  }
  public Employee(int newNumber, string newFirstName, string LastName){
    this.Number = newNumber;
    this.FirstName = newFirstName;
    this.LastName = LastName;
  }
}
class MainClass
{
  public static void Main() 
  {
    Employee emp = new Employee(1, "X", "F");
    emp.WriteEmployee();
    FileStream serializeStream = new FileStream("c:\\test.dat", FileMode.Create);
    BinaryFormatter bf = new BinaryFormatter();
    bf.Serialize(serializeStream, emp);
    serializeStream.Flush();
    serializeStream.Close();
    FileStream retrieveStream = new FileStream("c:\\test.dat", FileMode.Open);
    Employee NewEmployee = (Employee) bf.Deserialize(retrieveStream);
    NewEmployee.WriteEmployee();
  }
}
Number: 1
FirstName: X
LastName: F
Number: 1
FirstName: X
LastName: F