Use FileStream to write a file by byte array : File Byte Read Write « File Directory Stream « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. File Directory Stream
3. File Byte Read Write

using System;
using System.Windows.Forms;
using System.IO;

class MainClass
{
  public static void Main() 
  {
    FileStream inStream = File.OpenRead("C:\\test.txt");
    FileStream outStream = File.OpenWrite("C:\\test.txt" + ".bak");
    byte[] buf = new byte[4096];
    int bytesRead;

    while ((bytesRead = inStream.Read(buf, 0, 4096)) > 0)
      outStream.Write(buf, 0, bytesRead);

    outStream.Flush();
    outStream.Close();
    inStream.Close();

  }
}