#region 3DES        /// <summary>        /// 3DES加密        /// </summary>        /// <param name="strString">需加密的字符串</param>        /// <param name="strKey">密匙</param>        /// <returns></returns>        public static string DES3Encrypt(string strString, string strKey)        {            strString = strString + "".PadLeft(8);            byte[] bMsg = Encoding.GetEncoding("GBK").GetBytes(strString);            int l = (bMsg.Length / 16 + 1) * 16;            byte[] btMsg = new byte[l];            Array.Copy(bMsg, btMsg, bMsg.Length);            byte[] digestOfPassword = Encoding.Default.GetBytes(strKey);            byte[] keyBytes = new byte[24];            Array.Copy(digestOfPassword, keyBytes, digestOfPassword.Length);            for (int j = 0, k = 16; j < 8; )            {                keyBytes[k++] = keyBytes[j++];            }            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();            DES.Mode = CipherMode.ECB;            ICryptoTransform DESEncrypt = DES.CreateEncryptor(keyBytes, keyBytes);            var dd = DESEncrypt.TransformFinalBlock(btMsg, 0, btMsg.Length);            return byte2hex(dd).ToString().Substring(0, (bMsg.Length / 8 + 1) * 16);        }        public static String getAdd(int length, String strKey)        {            byte[] btMsg = new byte[length / 2];            byte[] digestOfPassword = Encoding.UTF8.GetBytes(strKey);            //byte[] digestOfPassword = Encoding.Default.GetBytes(strKey);            byte[] keyBytes = new byte[24];            Array.Copy(digestOfPassword, keyBytes, digestOfPassword.Length);            for (int j = 0, k = 16; j < 8; )            {                keyBytes[k++] = keyBytes[j++];            }            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();            DES.Mode = CipherMode.ECB;            ICryptoTransform DESEncrypt = DES.CreateEncryptor(keyBytes, keyBytes);            var dd = DESEncrypt.TransformFinalBlock(btMsg, 0, btMsg.Length);            String rtn = byte2hex(dd);            return rtn.Substring(length);        }        /// <summary>         /// 字节数组转16进制字符串         /// </summary>         /// <param name="bytes"></param>         /// <returns></returns>         private static string byte2hex(byte[] dd)        {            StringBuilder ret = new StringBuilder();            foreach (var item in dd)            {                ret.AppendFormat("{0:X2}", item);            }            return ret.ToString();        }        /// <summary>         /// 字符串转16进制字节数组         /// </summary>         /// <param name="hexString"></param>         /// <returns></returns>         private static byte[] strToToHexByte(string hexString)        {            hexString = hexString.Replace(" ", "");            if ((hexString.Length % 2) != 0)                hexString += " ";            byte[] returnBytes = new byte[hexString.Length / 2];            for (int i = 0; i < returnBytes.Length; i++)                returnBytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);            return returnBytes;        }        /// <summary>        /// 3DES解密        /// </summary>        /// <param name="strString">需解密的字符串</param>        /// <param name="strKey">密匙</param>        /// <returns></returns>        public static string DES3Decrypt(string strString, string strKey)        {            strString += getAdd(strString.Length, strKey);            byte[] digestOfPassword = Encoding.Default.GetBytes(strKey);            byte[] keyBytes = new byte[24];            Array.Copy(digestOfPassword, keyBytes, digestOfPassword.Length);            for (int j = 0, k = 16; j < 8; )            {                keyBytes[k++] = keyBytes[j++];            }            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();            DES.Mode = CipherMode.ECB;            ICryptoTransform DESDecrypt = DES.CreateDecryptor(keyBytes, keyBytes);            string result = "";            try            {                byte[] Buffer = strToToHexByte(strString);                byte[] bb = DESDecrypt.TransformFinalBlock(Buffer, 0, Buffer.Length);                result = Encoding.GetEncoding("GBK").GetString(bb);            }            catch (Exception e)            {                throw e;            }            return result;        }        #endregion