//DES加密public string DESEncrypt(string  pToEncrypt,  string  sKey)  ...{     DESCryptoServiceProvider  des  =  new  DESCryptoServiceProvider();     byte[]  inputByteArray  =  Encoding.Default.GetBytes(pToEncrypt);     des.Key  =  ASCIIEncoding.ASCII.GetBytes(sKey);     des.IV  =  ASCIIEncoding.ASCII.GetBytes(sKey);     MemoryStream  ms  =  new  MemoryStream();     CryptoStream  cs  =  new  CryptoStream(ms,  des.CreateEncryptor(),CryptoStreamMode.Write);     cs.Write(inputByteArray,  0,  inputByteArray.Length);     cs.FlushFinalBlock();     StringBuilder  ret  =  new  StringBuilder();     foreach(byte  b  in  ms.ToArray())     ...{      ret.AppendFormat("{0:X2}",  b);     }     ret.ToString();     return  ret.ToString();    }//DES解密  public string DESDecrypt(string  pToDecrypt,  string  sKey)  ...{    DESCryptoServiceProvider  des  =  new  DESCryptoServiceProvider();      byte[]  inputByteArray  =  new  byte[pToDecrypt.Length  /  2];     for(int  x  =  0;  x  <  pToDecrypt.Length  /  2;  x++)     ...{      int  i  =  (Convert.ToInt32(pToDecrypt.Substring(x  *  2,  2),  16));      inputByteArray[x]  =  (byte)i;     }      des.Key  =  ASCIIEncoding.ASCII.GetBytes(sKey);     des.IV  =  ASCIIEncoding.ASCII.GetBytes(sKey);     MemoryStream  ms  =  new  MemoryStream();     CryptoStream  cs  =  new  CryptoStream(ms,  des.CreateDecryptor(),CryptoStreamMode.Write);     cs.Write(inputByteArray,  0,  inputByteArray.Length);     cs.FlushFinalBlock();      StringBuilder  ret  =  new  StringBuilder();                  return  System.Text.Encoding.Default.GetString(ms.ToArray());    }