public class TrialHelper  {    //默認密鑰向量    private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };    /// <summary>    /// DES加密字符串    /// </summary>    /// <param name="encryptString">待加密的字符串</param>    /// <param name="encryptKey">加密密鑰,要求為8位</param>    /// <returns>加密成功返回加密后的字符串，失敗返回源串</returns>    public static string EncryptDES( string encryptString, string encryptKey = "" )    {      try      {        if (string.IsNullOrEmpty(encryptKey) || encryptKey.Length < 8)        {          encryptKey = "winform01";        }        byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));        byte[] rgbIV = Keys;        byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);        DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();        MemoryStream mStream = new MemoryStream();        CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);        cStream.Write(inputByteArray, 0, inputByteArray.Length);        cStream.FlushFinalBlock();        return Convert.ToBase64String(mStream.ToArray());      }      catch      {        return encryptString;      }    }    /// <summary>    /// DES解密字符串    /// </summary>    /// <param name="decryptString">待解密的字符串</param>    /// <param name="decryptKey">解密密鑰,要求為8位,和加密密鑰相同</param>    /// <returns>解密成功返回解密后的字符串，失敗返源串</returns>    public static string DecryptDES( string decryptString, string decryptKey = "" )    {      try      {        if (string.IsNullOrEmpty(decryptKey) || decryptKey.Length < 8)        {          decryptKey = "winform01";        }        byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.Substring(0, 8));        byte[] rgbIV = Keys;        byte[] inputByteArray = Convert.FromBase64String(decryptString);        DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();        MemoryStream mStream = new MemoryStream();        CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);        cStream.Write(inputByteArray, 0, inputByteArray.Length);        cStream.FlushFinalBlock();        return Encoding.UTF8.GetString(mStream.ToArray());      }      catch      {        return decryptString;      }    }    /// <summary>    /// MD5數據加密    /// </summary>    /// <param name="sDataIn">加密字段</param>    /// <returns>加密后的字符串</returns>    public static string GetMD5( string sDataIn )    {      System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();      byte[] bytValue, bytHash;      bytValue = System.Text.Encoding.UTF8.GetBytes(sDataIn);      bytHash = md5.ComputeHash(bytValue);      md5.Clear();      string sTemp = "";      for (int i = 0; i < bytHash.Length; i++)      {        sTemp += bytHash[i].ToString("x").PadLeft(2, '0');      }      return sTemp;    }  }

//獲取登錄信息        loginRecord.Name = tbName.Text.Trim();        loginRecord.MD5Pwd = TrialHelper.GetMD5(tbPwd.Password); //保存到數據庫MD5加密方式        loginRecord.Pwd = TrialHelper.EncryptDES(tbPwd.Password);//記住密碼des加密方式，保存到本地