If s.Length = s.Position Then
    Console.WriteLine("End of file has been reached.")
End If

' 导入命名空间
Imports System
Imports System.IO

Public Class MainClass

  Shared Sub Main()

    Dim i As Integer
    Dim theBytes(255) As Byte
    For i = 0 To 255
      theBytes(i) = CByte(i)
    Next
    Dim myFileStream As FileStream
    Try
      myFileStream = New FileStream("test.txt", FileMode.OpenOrCreate, FileAccess.Write)
      myFileStream.Write(theBytes, 0, 256)
    Finally
      If Not (myFileStream Is Nothing) Then myFileStream.Close()
    End Try


    Dim theFile As FileStream
    Try
      theFile = New FileStream("test.txt",FileMode.Open, FileAccess.Read)
      For i = 0 To (theFile.Length - 1)
        Console.Write(theFile.ReadByte)
      Next
    Catch e As Exception
      Throw e
    Finally
      If Not (theFile Is Nothing) Then theFile.Close()
    End Try
  End Sub
  
End Class