using System;

using System.Text;

using System.Linq;

using System.IO;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Encoding utf8BOM = Encoding.UTF8;

        Encoding utf8 = new UTF8Encoding(false);

​

        String unicodeString =

            "This Unicode string has 2 characters outside the " +

            "ASCII range:\n" +

            "Pi (\u03A0)), and Sigma (\u03A3).";

        Console.WriteLine("Original string:");

        Console.WriteLine(unicodeString);

        Console.WriteLine();

        var bomStream = new MemoryStream();

        using (var bomSW = new StreamWriter(bomStream, utf8BOM))

        {

            bomSW.Write(unicodeString);

        }

​

        var stream = new MemoryStream();

        using (var SW = new StreamWriter(stream, utf8))

        {

            SW.Write(unicodeString);

        }

        Console.WriteLine(string.Join(" ", bomStream.ToArray().Take(10).Select(x => string.Format("{0:X2}", x))));

        Console.WriteLine(string.Join(" ", stream.ToArray().Take(10).Select(x => string.Format("{0:X2}", x))));

    }

}