content come from http://jashliao.pixnet.net/blog/post/223529346
using System;
public class Example
{
public static void Main()
{
// Define a byte array.
byte[] bytes = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
Console.WriteLine("The byte array: ");
Console.WriteLine(" {0}\n", BitConverter.ToString(bytes));
// Convert the array to a base 64 sring.
String s = Convert.ToBase64String(bytes);
Console.WriteLine("The base 64 string:\n {0}\n", s);
// Restore the byte array.
byte[] newBytes = Convert.FromBase64String(s);
Console.WriteLine("The restored byte array: ");
Console.WriteLine(" {0}\n", BitConverter.ToString(newBytes));
}
}
// The example displays the following output:
// The byte array:
// 02-04-06-08-0A-0C-0E-10-12-14
//
// The base 64 string:
// AgQGCAoMDhASFA==
//
// The restored byte array:
// 02-04-06-08-0A-0C-0E-10-12-14