private static void EncryptData(String inName, String outName, byte[] desKey, byte[] desIV)
   {   
       //Create the file streams to handle the input and output files.
  
       FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
       FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
       fout.SetLength(0);
  
       //Create variables to help with read and write.
  
       byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
  
       long rdlen = 0;              //This is the total number of bytes written.
  
       long totlen = fin.Length;    //This is the total length of the input file.
  
       int len;                     //This is the number of bytes to be written at a time.
  
  
       DES des = new DESCryptoServiceProvider();         
       CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);
  
       Console.WriteLine("Encrypting...");
  
       //Read from the input file, then encrypt and write to the output file.
  
       while(rdlen < totlen)
       {
           len = fin.Read(bin, 0, 100);
          encStream.Write(bin, 0, len);
           rdlen = rdlen + len;
           Console.WriteLine("{0} bytes processed", rdlen);
       }
  
       encStream.Close();  
       fout.Close();
       fin.Close();                  
   }
 这是一个DES加密的代码，我现在需要把“encStream.Write(bin, 0, len);”写成一个函数调用的形式，其调用的就是DES加密的源代码（即为DES加密的过程、转换、生成密码）
随便问下放过来解密的代码