[Qt-interest] GIF and JPG failing under Windows 7

[Oliver.Knoll at comit.ch]

On 2010-10-20 Bob Bob Babcock wrote:

> Thanks.  I found qjpeg4.dll and qgif4.dll and added them to imageformats
> under the application directory.  Then it works.  I didn't know this was
> necessary since I haven't needed to do this under XP.

Because you had the Qt development environment setup there, see below ;)  I don't know the details, but there are some "default" places Qt looks for plugins, the Qt installation (Via registry? Via QTDIR environment variable? Encoded into the Qt DLLs?) directory being one of them.

> Perhaps having a
> build environment setup is enough to let Windows find the dlls.

That's exactly the reason.

But in general read this: http://doc.trolltech.com/4.7/deployment.html and specifically http://doc.trolltech.com/4.7/plugins-howto.html#locating-plugins

Also in general on Windows "dependency walker" is your friend (part of the Windows SDK or freely available here as well: http://www.dependencywalker.com/ (it does not help you with plugins though, since they are located at runtime using application specific logic, e.g. specific plugin directories etc.).

Cheers, Oliver
--
Oliver Knoll
Dipl. Informatik-Ing. ETH
COMIT AG - ++41 79 520 95 22