How to encrypt data from URL

Class AES
  {        
    public void EncryptFile(string inputFile, string  outputfile, string hoskeys)
       {
      try
      {
          //if(!File.Exists(outputfile))
          //    File.Create(outputfile);
          // Create the password key
        byte[]  saltValueBytes = Encoding.ASCII.GetBytes("This is my salt");
    Rfc2898DeriveBytes passwordKey = new Rfc2898DeriveBytes(hoskeys, saltValueBytes);
        // Create the algorithm and specify the key and IV
        RijndaelManaged alg = new RijndaelManaged();
        alg.Key = passwordKey.GetBytes(alg.KeySize/8);
        alg.IV = passwordKey.GetBytes(alg.BlockSize/8);
        // Read the unencrypted file into fileData
        FileStream inFile = new FileStream(inputFile, FileMode.Open, FileAccess.Read);
        byte[]  fileData = new byte[inFile.Length];
        inFile.Read(fileData, 0, (int)inFile.Length);
        // Create the ICryptoTransform and CryptoStream object
        ICryptoTransform encryptor = alg.CreateEncryptor();
        FileStream outFile = new FileStream( outputfile, FileMode.OpenOrCreate, FileAccess.Write);
        CryptoStream encryptStream = new CryptoStream(outFile, encryptor, CryptoStreamMode.Write);        
        // Write the contents to the CryptoStream
        encryptStream.Write(fileData, 0, fileData.Length);
        // Close the file handles
        encryptStream.Close();
        inFile.Close();
        outFile.Close();
        } 
       catch(Exception ex)
        {
            //MessageBox.Show("Encryption failed!", "Error");
            Console.WriteLine("");
        }
    }

//calling in main function

  Encrypt_and_decrypt.AES e = new AES();

   e.EncryptFile("http://192.168.....","E:\\folder","hkeys");