CSharp. Base64 string Encoding and Decoding

    public class Converter
    {
        public static String EncodingBase64(String str)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(str);
            string base64 = Convert.ToBase64String(bytes);
            return base64;
        }

        public static String DecodeFromBase64(String str)
        {
            byte[] buffer = Convert.FromBase64String(str);
            string s = System.Text.Encoding.UTF8.GetString(buffer, 0, buffer.Length);
            return s;
        }
    }
}