Qt4 plugin path problem

[david.corinex]

I have a problem with QT4 plugin path which is hard-coded into QtCore4.dll directly. I have tried to use addLibraryPath or setLibraryPaths but both didn't work. The only way I can make it work is change the hard-coded path in QtCore4.dll using a hex editor but I don't think it is a good way. Does anyone have a good solution on it?

Thanks

[jacek]

When do you invoke that method? QCoreApplication loads plugins when you create its instance. Adding a path after the plugins were loaded won't help.

Also Qt docs say:

You can also use a qt.conf file to override the hard-coded paths that are compiled into the Qt library. For more information, see the Using qt.conf documentation. Yet another possibility is to set the QT_PLUGIN_PATH environment variable before running the application. If set, Qt will look for plugins in the paths (separated by the system path separator) specified in the variable.

[david.corinex]

I invoked the function right after QApplication a(argc, argv);
Here is my code:

QApplication a(argc, argv);
QString path;
path = QCoreApplication::applicationDirPath();
QCoreApplication::addLibraryPath(path);

I tried to call that function before initiating the qApplication:
path = QCoreApplication::applicationDirPath();
QCoreApplication::addLibraryPath(path);

QApplication a(argc, argv);

But I got the following error message:
QCoreApplication::applicationDirPath: Please instantiate the QApplication object first

That's all I got so far.

[jacek]

You don't have to add applicationDirPath() to library paths --- it's already there. Just make sure that plugins are in proper subdirectories.

Which plugins do you need?

[david.corinex]

I need gif and jpeg plugins which are stored in \QTDIR\plugins\imageformat directory. Actually these plugins are called by QtCore4.dll, instead of my program. I want to put all these DLLs to the program folder when I deploy the application. Now, I have to change the hard-corded plugpath in QtCore4.dll and install the plugin dll into a fixed folder such as c:\qt4\plugins.

My goal is to put plugin DLLs to the folder that stores my exe file. That's why I add applicatioon path to the LibraryPath.

Thanks for your help:-)

David

[jacek]

My goal is to put plugin DLLs to the folder that stores my exe file.

If xxx is one of the "library" paths, Qt will look for image plugins in xxx/imageformats subdirectory.

What does QCoreApplication::libraryPaths() return on your system?

[david.corinex]

Oh my....

I forgot QtCore4.dll will search plugins in /newpathdir/imageformats directory. I will try this today:-)

Thanks for your great hints!
David