エクスプローラの縮小版を表示する方法について

渋木宏明(ひどり)さんの書き込み (2007-10-03 13:16) より:
最新のドキュメントは
Thumbnail Providers
http://msdn2.microsoft.com/en-us/library/bb776855.aspx
のようです。
詳しくは調べていませんが、IExtractImage2 は Vista で扱いが変わったようで「動かなくなった」的な事例をいくつかみかけました。

The IThumbnailProvider interface has been introduced to make providing a thumbnail easier and more straightforward than in the past, when IExtractImage or IExtractImage2 would have been used instead. Note, however, that existing code that uses IExtractImage or IExtractImage2 is still valid under Windows Vista.

一応、VistaでもIExtractImage/IExtractImage2は有効だとは記述されていますが…

もずみんさんの書き込み (2007-10-03 22:49) より:
予想はしていたのですが、やはりC++で実装すべきなのですね。

Tdnr_Symの書き込み (2007-10-03 13:02) より:
見失いましたが、検索しているときに、どっかの英語の掲示板で
「.NETでは危険だからアンマネージのC++で開発してね。１つのプロセスでロードできる.NETのバージョンは１つだから…」
みたいなことが書いてありました。

Jesse Kaplanさん（モデレータ）の書き込み
Unfortunately unmanaged C++ is really the only way to go here.
Writing in-process shell extensions in managed code is actually a very dangerous thing to do because it has the effect of injecting your managed code (and the .NET Framework) into every application on the machine that has a file open dialog.
The problems occur because only one version of the .NET Framework can be loaded in a process at any given time (other shared components such as java and msxml have the same property and thus the same restriction).
If you write your shell extension using the 2.0 .NET Framework and an application built with the 1.1 .NET Framework uses a file open dialog, your shell extension will fail because it can not run on an earlier version. Things can get even worse if your shell-extension manages to get loaded in a process before another applications managed code does: your extension may force an existing application onto a different runtime version than the one it was expecting and cause it to fail.
Because of these problems we strongly recomend against using any single-instance-per-process runtime or library (such as the .NET Framework, java, or msxml) in an in-process shell extension.