public static string Encrypt(string plainText, string AESKey){  RijndaelManaged rijndaelCipher = new RijndaelManaged();  byte[] inputByteArray = Encoding.UTF8.GetBytes(plainText);//得到需要加密的字節數組  rijndaelCipher.Key = Convert.FromBase64String(AESKey);//加解密雙方約定好密鑰：AESKey  rijndaelCipher.GenerateIV();  byte[] keyIv = rijndaelCipher.IV;  byte[] cipherBytes = null;  using (MemoryStream ms = new MemoryStream())  {    using (CryptoStream cs = new CryptoStream(ms, rijndaelCipher.CreateEncryptor(), CryptoStreamMode.Write))    {      cs.Write(inputByteArray, 0, inputByteArray.Length);      cs.FlushFinalBlock();      cipherBytes = ms.ToArray();//得到加密后的字節數組      cs.Close();      ms.Close();    }  }  var allEncrypt = new byte[keyIv.Length + cipherBytes.Length];  Buffer.BlockCopy(keyIv, 0, allEncrypt, 0, keyIv.Length);  Buffer.BlockCopy(cipherBytes, 0, allEncrypt, keyIv.Length * sizeof(byte), cipherBytes.Length);  return Convert.ToBase64String(allEncrypt);} public static string Decrypt(string showText, string AESKey){  string result = string.Empty;  try  {    byte[] cipherText = Convert.FromBase64String(showText);    int length = cipherText.Length;    SymmetricAlgorithm rijndaelCipher = Rijndael.Create();    rijndaelCipher.Key = Convert.FromBase64String(AESKey);//加解密雙方約定好的密鑰    byte[] iv = new byte[16];    Buffer.BlockCopy(cipherText, 0, iv, 0, 16);    rijndaelCipher.IV = iv;    byte[] decryptBytes = new byte[length - 16];    byte[] passwdText = new byte[length - 16];    Buffer.BlockCopy(cipherText, 16, passwdText, 0, length - 16);    using (MemoryStream ms = new MemoryStream(passwdText))    {      using (CryptoStream cs = new CryptoStream(ms, rijndaelCipher.CreateDecryptor(), CryptoStreamMode.Read))      {        cs.Read(decryptBytes, 0, decryptBytes.Length);        cs.Close();        ms.Close();      }    }    result = Encoding.UTF8.GetString(decryptBytes).Replace("/0", "");  ///將字符串后尾的'/0'去掉  }  catch { }  return result;}

string jiaMi = MyAESTools.Encrypt(textBox1.Text, "abcdefgh12345678abcdefgh12345678"); string jieMi = MyAESTools.Decrypt(textBox3.Text, "abcdefgh12345678abcdefgh12345678");