Vista ThumbnailProvider and IInitializeWithStream

[GibbsJeremyS]

So I've been beating my head against a wall for the past few days trying to get this to work. I've tried countless samples from the net and even the MSDN sample.

I just can't get it to work, Explorer NEVER seems to call my DLL. I recently created another Explorer extension for the Preview Pane and that went pretty smoothly, but I just can't figure out what's going wrong.

I've tried 32-bit systems, visual studio 2005 & 2008, nothing seems to work. The registration goes smoothly, I add the necessary registry nodes, but the DLL is never called. I had another developer try the MSDN sample as well, with no success. Does anyone have any ideas?

Thanks

[GibbsJeremyS]

So many views and no replies...well here's a bit more info:

I'm on a 64 bit system, I opened up a 32bit app and low and behold the thumbnails start to generate when I go to File->Open of that app.

So, I start digging around the registry thinking maybe I just added it to the 32 bit hive, but I see the registry settings to be the same in both hives. I'm now quite perplexed.

[GibbsJeremyS]

And now I find the solution.

To anyone that has this problem you need to register your DLL with the 64 bit version of regasm as well.

the 64 bit version of regasm should be in,
C:\windows\microsoft.net\Framework64\v2.0.50727\regasm.exe

[DdoubleD]

Many of us don't have 64 bit systems, so I'm not surprised you didn't get input. Anyway, just wanted to say thanks for posting your solution because many just say they solved it themselves and that's it.

Cheers!

[GibbsJeremyS]

Many of us don't have 64 bit systems, so I'm not surprised you didn't get input. Anyway, just wanted to say thanks for posting your solution because many just say they solved it themselves and that's it.

Cheers!

That's cool, and I understand that the 64bit OS hasn't gotten a lot of market penetration as of yet.

I wanted to post the solution in case anyone else had this problem and was able to google enough to stumble across this thread :), had I found one like this last week I would have slept a lot better over the weekend LOL :)

[DdoubleD]

Incidentally, I ran across many blogs indicating you shouldn't create extensions using managed code. I was reading up on the subject somewhat before you indicated you had it solved. I was wondering whether you have considered these concerns and you are confident you won't have the issues they discuss?

[GibbsJeremyS]

Incidentally, I ran across many blogs indicating you shouldn't create extensions using managed code. I was reading up on the subject somewhat before you indicated you had it solved. I was wondering whether you have considered these concerns and you are confident you won't have the issues they discuss?

The problem that exists with that is still present, I agree ( though you can write the preview pane extension in managed code and it is always loaded out of process, but I am writing my shell extension that uses all 1.1 framework calls, and should be fully backwards compatible, even if a different .net extension loads first.

Yes, it would have been "better" for it to be written in straight COM, but with the way I have written mine I don't expect any issues.

:)

[GibbsJeremyS]

Also, to note. In Vista the Thumbnail Process DOES run out of process by default:

http://msdn.microsoft.com/en-us/library/cc144118%28VS.85%29.aspx

Thumbnail Processes

Handlers, including thumbnail providers, run by default in a separate process.