public class Encrypt

    {

        public static byte[] ToEncrypt(string encryptKey, byte[] P_byte_data)

        {

            try

            {

                byte[] P_byte_key = Encoding.Unicode.GetBytes(encryptKey);//将密钥字符串转换为字节序列

                MemoryStream P_Stream_MS = new MemoryStream(); //创建内存流对象

                CryptoStream P_CryptStream_Stream = new CryptoStream(P_Stream_MS, new DESCryptoServiceProvider().CreateEncryptor(P_byte_key, P_byte_key), CryptoStreamMode.Write);//创建加密流对象

                P_CryptStream_Stream.Write(P_byte_data, , P_byte_data.Length);//向加密流中写入字节序列

                P_CryptStream_Stream.FlushFinalBlock();//将数据压入基础流

                byte[] P_bt_temp = P_Stream_MS.ToArray();//从内存流中获取字节序列

                P_CryptStream_Stream.Close();//关闭加密流

                P_Stream_MS.Close();//关闭内存流

                return P_bt_temp;//方法返回加密后的byte

            }

            catch (CryptographicException ce)

            {

                throw new Exception(ce.Message);

            }

        }

        public static byte[] ToDecrypt(string encryptKey, byte[] P_byte_data)

        {

            try

            {

                byte[] P_byte_key = Encoding.Unicode.GetBytes(encryptKey); //将密钥字符串转换为字节序列

                MemoryStream P_Stream_MS = new MemoryStream(P_byte_data);//创建内存流对象并写入数据

                CryptoStream P_CryptStream_Stream = new CryptoStream(P_Stream_MS, new DESCryptoServiceProvider().CreateDecryptor(P_byte_key, P_byte_key), CryptoStreamMode.Read);//创建加密流对象

                byte[] P_bt_temp = new byte[];//创建字节序列对象

                MemoryStream P_MemoryStream_temp = new MemoryStream();//创建内存流对象

                int i = ;//创建记数器

                while ((i = P_CryptStream_Stream.Read(P_bt_temp, , P_bt_temp.Length)) > )//使用while循环得到解密数据

                {

                    P_MemoryStream_temp.Write(P_bt_temp, , i);//将解密后的数据放入内存流

                }

                return P_MemoryStream_temp.ToArray();//方法返回解密后的byte

            }

            catch (CryptographicException ce)

            {

                throw new Exception(ce.Message);

            }

        }