Use MemoryStream with BinaryWriter and BinaryReader : MemoryStream « Stream File « VB.Net Tutorial

1. VB.Net Tutorial
2. Stream File
3. MemoryStream

Imports System.IO

public class Test
   public Shared Sub Main
        Dim memory_stream As New MemoryStream()
        Dim binary_writer As New BinaryWriter(memory_stream)
        binary_writer.Write("aaa.")

        Dim binary_reader As New BinaryReader(memory_stream)
        memory_stream.Seek(0, SeekOrigin.Begin)
        Console.WriteLine(binary_reader.ReadString())
        binary_reader.Close()


   End Sub
End class

aaa.