[c#] Base64Encoding, Base64Decoding

    public static class Base64String
    {
        public static string Base64Encode(this string src, System.Text.Encoding enc)
        {
            byte[] arr = enc.GetBytes(src);
            return Convert.ToBase64String(arr);
        }

        public static string Base64Decode(this string src, System.Text.Encoding enc)
        {
            byte[] arr = Convert.FromBase64String(src);
            return enc.GetString(arr);
        }
    }