using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace Util.Extend

{

    /// <summary>

    /// 实现Base64加密解密

    /// </summary>

    public sealed class Base64

    {

        /// <summary>

        /// Base64加密

        /// </summary>

        /// <param name="code">加密采用的编码方式</param>

        /// <param name="source">待加密的明文</param>

        /// <returns></returns>

        public static string EncodeBase64(Encoding encode, string source)

        {

            string result = string.Empty;

            byte[] bytes = encode.GetBytes(source);

            try

            {

                result = Convert.ToBase64String(bytes);

            }

            catch

            {

                result = source;

            }

            return result;

        }

        /// <summary>

        /// Base64加密，采用utf8编码方式加密

        /// </summary>

        /// <param name="source">待加密的明文</param>

        /// <returns>加密后的字符串</returns>

        public static string EncodeBase64(string source)

        {

            return EncodeBase64(Encoding.UTF8, source);

        }

        /// <summary>

        /// Base64解密

        /// </summary>

        /// <param name="codeName">解密采用的编码方式，注意和加密时采用的方式一致</param>

        /// <param name="result">待解密的密文</param>

        /// <returns>解密后的字符串</returns>

        public static string DecodeBase64(Encoding encode, string result)

        {

            string decode = "";

            byte[] bytes = Convert.FromBase64String(result);

            try

            {

                decode = encode.GetString(bytes);

            }

            catch

            {

                decode = result;

            }

            return decode;

        }

        /// <summary>

        /// Base64解密，采用utf8编码方式解密

        /// </summary>

        /// <param name="result">待解密的密文</param>

        /// <returns>解密后的字符串</returns>

        public static string DecodeBase64(string result)

        {

            return DecodeBase64(Encoding.UTF8, result);

        }

    }

}

Base64.EncodeBase64(targetString);