/// <summary>
        /// 实现对字符串加密解密
        /// </summary>
        /// <remarks></remarks>
        public class Encrypt
        {
            private SymmetricAlgorithm mCSP;
            private const string CIV = "kXwL7X2+fgm=";//密钥
            private const string CKEY = "FwGQWRRgKCI=";//初始化向量


            /// <summary>
            /// 初始化类的新实例。
            /// </summary>
            /// <remarks></remarks>
            public Encrypt()
            {
                mCSP = new DESCryptoServiceProvider();
            }

            /// <summary>
            /// 对字符串加密
            /// </summary>
            /// <param name="value">要加密的字符串</param>
            /// <returns>string</returns>
            /// <remarks></remarks>
            public string EncyptString(string value)
            {
                ICryptoTransform ct; //加密器
                MemoryStream ms;
                CryptoStream cs;
                byte[] byt;
                ct = mCSP.CreateEncryptor(Convert.FromBase64String(CKEY), Convert.FromBase64String(CIV));
                byt = Encoding.UTF8.GetBytes(value);//将加密的字符串放到字节流中
                ms = new MemoryStream();
                cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
                cs.Write(byt, 0, byt.Length);
                cs.FlushFinalBlock();
                cs.Close();
                return Convert.ToBase64String(ms.ToArray());
            }

            /// <summary>
            /// 解密
            /// </summary>
            /// <param name="value">The value.</param>
            /// <returns></returns>
            /// <remarks></remarks>
            public string Decryption(string value)
            {
                ICryptoTransform ct; //加密器
                MemoryStream ms;
                CryptoStream cs;
                byte[] byt;

                ct = mCSP.CreateDecryptor((Convert.FromBase64String(CKEY)), Convert.FromBase64String(CIV));
                byt=Convert.FromBase64String(value);

                ms=new MemoryStream();
                cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);//解密流
                cs.Write(byt,0,byt.Length);
                cs.FlushFinalBlock();
                cs.Close();
                return Encoding.UTF8.GetString(ms.ToArray());
        }