How to retrieve the file previews used by windows explorer in Windows vista and seven?

Question

I am developing a Delphi documents management application, so somehow I am giving the user some functionality similar to windows explorer.

I would like to know if there is a way to get the preview used by windows explorer. For example windows explorer creates a small thumbnail for a pdf document for example, and displays it when the user chooses to view "big icons". Is there a way to retrieve that preview?

MyTImage := GiveMePreviewForFile('C:\Test\File.pdf');

Wien

Possible dupe (first question): #830343 – Trial

Sorry you are right. I reformulated the question. Thanks. – Wien

Answer 1

@user193655, using the IExtractImage interface is the way to go, this interface exposes methods that request a thumbnail image from a Shell folder

you can find a very complete sample in this site and the source code is here.

check this image

Binni

At the moment, the source code can still be downloaded from archive.org: web.archive.org/web/20060115070800/http://www.delphi3000.com/… – Casebound

Note that the code above from Hans Gulo works, but is very slow, taking around 500 to 1000 ms :-( The slowness occurs when calling the Extract function on line 24 of ShObjIdlQuot.pas. – Colossae

Both Hans and Microsoft mention that you can call Kill to abort the process, but it's not clear how to do that or whether you still get a result. – Colossae

To use Hans Gulo's code in a thread, you must first initialize the COM engine by calling CoInitialize(), then free it by calling CoUninitialize(); – Colossae

Answer 2

Take a look at the docs for IExtractImage. Basically you use IShellFolder with IExtractImage to get the picture you are looking for.

Oshaughnessy