using System;using System.Text;namespace Common{  /// <summary>  /// 實現Base64加密解密  /// 作者：周公  /// </summary>  public sealed class Base64  {    /// <summary>    /// Base64加密    /// </summary>    /// <param name="codeName">加密采用的編碼方式</param>    /// <param name="source">待加密的明文</param>    /// <returns></returns>    public static string EncodeBase64(Encoding encode, string source)    {      byte[] bytes = encode.GetBytes(source);      try      {        encode = Convert.ToBase64String(bytes);      }      catch      {        encode = source;      }      return encode;    }    /// <summary>    /// Base64加密，采用utf8編碼方式加密    /// </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">解密采用的編碼方式，注意和加密時采用的方式一致</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編碼方式解密    /// </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);    }  }}