using System;

public class Program

{

    //https://stackoverflow.com/questions/21325661/convert-image-path-to-base64-string

    public static void Main()

    {

     string base64Decoded;

     string s="YmFzZTY0IGRlY29kZXI"; // encoded value for 'base64 decoder'

     int mod4 = s.Length % 4;

if (mod4 > 0 )

{

    s += new string('+', 4 - mod4);

}

        Console.WriteLine(s);   

       // Restore the byte array.

       byte[] newBytes = Convert.FromBase64String(s);

       Console.WriteLine("The restored byte array: ");

       Console.WriteLine("   {0}\n", BitConverter.ToString(newBytes));

       base64Decoded = System.Text.ASCIIEncoding.ASCII.GetString(newBytes);

       Console.WriteLine(base64Decoded);

       Console.WriteLine("The base 64 string:\n   {0}\n", Convert.ToBase64String(newBytes));

    }

}