VB.Net FileStream Class

Imports System.IO
Module fileProg
   Sub Main()
      Dim f1 As FileStream = New FileStream("sample.txt", _
              FileMode.OpenOrCreate, FileAccess.ReadWrite)
      Dim i As Integer
      For i = 0 To 20
          f1.WriteByte(CByte(i))
      Next i
      f1.Position = 0
      For i = 0 To 20
          Console.Write("{0} ", f1.ReadByte())
      Next i
      f1.Close()
      Console.ReadKey()
   End Sub
End Module