/// <summary>
        /// 對數(shù)據(jù)進行加密
        /// </summary>
        /// <param name="encryptstring">需要加密的數(shù)據(jù)</param>
        /// <returns></returns>
        public string DESEncrypt(string encryptstring)
        {
            string strRtn;
            try
            {
                DESCryptoServiceProvider desc = new DESCryptoServiceProvider();   //des進行加密
                PasswordDeriveBytes encryptkey = new PasswordDeriveBytes(encryptstring, null);//產(chǎn)生key
                byte[] key = encryptkey.GetBytes(8);
                byte[] data = System.Text.Encoding.Unicode.GetBytes(encryptstring);//取到密碼的字節(jié)流
                MemoryStream ms = new MemoryStream();                            //用來存儲加密后的數(shù)據(jù)                           
                CryptoStream cs = new CryptoStream(ms, desc.CreateEncryptor(key, key), CryptoStreamMode.Write); //進行加密
                cs.Write(data,0,data.Length );
                cs.FlushFinalBlock();                                            //用緩沖區(qū)的當前狀態(tài)更新基礎數(shù)據(jù)源或存儲庫，隨后清除緩沖區(qū)
                strRtn = Convert.ToBase64String(ms.ToArray());                   //將整個流內(nèi)容寫入字節(jié)數(shù)組,轉(zhuǎn)換到字符串返回
                return strRtn;
            }
            catch (Exception ex)
            {
                //彈出捕獲的異常信息
                MessageBox.Show("錯誤："+ex.Message ,"錯誤消息提示框",MessageBoxButtons.OKCancel,MessageBoxIcon.Error );
                return null ;
            }
        }

        /// <summary>
        /// 對數(shù)據(jù)進行解密
        /// </summary>
        /// <param name="decryptstring">需要解密的數(shù)據(jù)</param>
        /// <returns></returns>
        public string DESDecrypt(string decryptstring)
        {
            string strRtn;
            try
            {
                //定義訪問數(shù)據(jù)加密標準（DES）算法的加密服務提供程序（CSP）版本的包裝對象
                DESCryptoServiceProvider desc = new DESCryptoServiceProvider();
                PasswordDeriveBytes encryptkey = new PasswordDeriveBytes(decryptstring, null);//產(chǎn)生key
                byte[] key = encryptkey.GetBytes(8);
                byte[] data = Convert.FromBase64String(decryptstring);
                MemoryStream ms = new MemoryStream();                            //用來存儲解密后的數(shù)據(jù)                           
                CryptoStream cs = new CryptoStream(ms, desc.CreateEncryptor(key, key), CryptoStreamMode.Write);
                cs.Write(data, 0, data.Length);                                  //進行解密
                cs.FlushFinalBlock();                                            //用緩沖區(qū)的當前狀態(tài)更新基礎數(shù)據(jù)源或存儲庫，隨后清除緩沖區(qū)
                strRtn = System.Text.Encoding.Unicode.GetString(ms.ToArray());   //將整個流內(nèi)容寫入字節(jié)數(shù)組
                return strRtn;
            }
            catch (Exception ex)
            {
                //彈出捕獲的異常信息
                MessageBox.Show("錯誤：" + ex.Message, "錯誤消息提示框", MessageBoxButtons.OKCancel, MessageBoxIcon.Error);
                return null;
            }
        }