Adobe Reader XI & iFilter indexing

Question

In Adobe Reader X they removed the ability to do iFilter indexing from the Windows Indexing services of PDF files.  To get around this you had to install Adobe Reader 9.x on 32bit systems or the iFilter 9 on 64bit systems.
Does anyone know if Adobe Reader XI follows the same stance of not exposing its iFilters to the Windows Indexing service?  I've done some searching but this answer does not seem to exist yet where I can find it.

Answer 1

There is an excellent article on working with IFilters in C#: Implementing a TextReader to extract various files contents using IFilter - CodeProject
As Adobe Reader XI IFilter doesn't support IPersistFile.Load(..) anymore because of Microsoft's requirement for IFilters to work with stream data instead of file data, it's a problem for custom file search engines like those built using Lucene.net.
The main point here is that you need to use IPersistStream for Adobe PDF IFilter 11.x instead of IPersistStore.
Here's a relevant discussion on the related topic at StackOverflow:
http://stackoverflow.com/questions/7313828/using-ifilter-in-c-sharp-and-retrieving-file-fr om-database-rather-than-file-syst[^]
I've used these two sets of recommendations to re-write the way how IFilter is obtained for PDF files. Obviously this solution isn't the best one (one could just provide bytes to FilterLoader instead), but at least it works (and doesn't break the logic).
There is also no check if filter is Adobe's or not, but such check should be done, as other PDF IFilters might not support IPersistStream. One should also check for its version (e.g., Adobe PDF IFilter 9.x supports IPersistFile w/o any problems).
Here's the updated code:
public static IFilter LoadIFilterFromIPersistFile(string path, string extension)
  var fileExt = System.IO.Path.GetExtension(path);
   // Obtaining IFilter first
IFilter filter = LoadIFilter(extension);
  if (null == filter) return null;  
// Custom case for PDF
if (fileExt == ".pdf")
  // read file first
using (var s = new FileStream(path, FileMode.Open))
  // Copy the content to global memory
byte[] buffer = new byte[s.Length];
  s.Read(buffer, 0, buffer.Length);
  IntPtr nativePtr = Marshal.AllocHGlobal(buffer.Length);
  Marshal.Copy(buffer, 0, nativePtr, buffer.Length);
   // Create a COM stream
System.Runtime.InteropServices.ComTypes.IStream comStream;
  CreateStreamOnHGlobal(nativePtr, true, out comStream);
   // Load the contents to the iFilter using IPersistStream interface
var persistStream = (IPersistStream)filter; // similar to persistFile case
if (null == persistStream)
  throw new Exception("IPersistStream is not implemented by the current interface");
  // loading
persistStream.Load(comStream);  
  return InitIFilterForPdf(filter);
  else
  var persistFile = (filter as IPersistFile);
  if (null == persistFile)
  throw new Exception("IPersistFile is not implemented by the current interface");
  persistFile.Load(path, 0);
return InitIFilter(filter);