public  string Encrypt(string str)        {            string result = null;            if (str == null)            {                return result;            }            try            {                byte[] array0 = Encoding.ASCII.GetBytes(str);                MemoryStream stream = new MemoryStream(array0);                RijndaelManaged rijndaelManaged = new RijndaelManaged();                byte[] key = new byte[32] { 5, 1, 3, 28, 27, 3, 2, 16, 12, 19, 39, 200, 10, 18, 181, 79, 103, 61, 145, 215, 125, 212, 131, 241, 229, 254, 250, 205, 11, 29, 83, 125 };                byte[] vi = new byte[16] { 204, 19, 18, 10, 147, 108, 20, 177, 26, 171, 19, 143, 38, 112, 19, 12 };                ICryptoTransform transform = rijndaelManaged.CreateEncryptor(key, vi);                CryptoStream cryptoStream = new CryptoStream(stream, transform, CryptoStreamMode.Write);                result = cryptoStream.ToString();                cryptoStream.FlushFinalBlock();                return result;            }            catch            {                return null;            }        }        public  string Decode(string str)        {            string result = null;            if (str == null)            {                return result;            }            try            {                byte[] array0 = Encoding.ASCII.GetBytes(str);                MemoryStream stream = new MemoryStream(array0);                RijndaelManaged rijndaelManaged = new RijndaelManaged();                byte[] key = new byte[32] { 5, 1, 3, 28, 27, 3, 2, 16, 12, 19, 39, 200, 10, 18, 181, 79, 103, 61, 145, 215, 125, 212, 131, 241, 229, 254, 250, 205, 11, 29, 83, 125 };                byte[] vi = new byte[16] { 204, 19, 18, 10, 147, 108, 20, 177, 26, 171, 19, 143, 38, 112, 19, 12 };                ICryptoTransform transform = rijndaelManaged.CreateEncryptor(key, vi);                CryptoStream inStream = new CryptoStream(stream, transform, CryptoStreamMode.Read);                return inStream.ToString();            }            catch            {                return null;            }        }

1.代码中key和vi分别对应加密器对象和初始化向量 ()

2.Key和VI只有完全匹配得上加密数据才可以被解密