where/what are static plugins?

[jacek]

Do you use qmake from the static Qt build?

[ht1]

Yes, indeed, I use QMAKE from static Qt build. Also, I am able to incorporate other static plugins no problem, just not the imageformat static plugins. Taking these plugins out makes the program to compile fine but unable to handle image files (because the plugins were not incorporated). So, I think the compiler is fine and the code is fine. It's either that imageformat plugins have a problem, or I do not declare them right, or they are not in the right folder.

[jacek]

Could you post the command used to link your application (the one where the g++ is invoked with -l options)?

Do you get any other error messages apart from "undefined reference to qt_plugin_instance_xxx"?

[ht1]

Great, Jacek, you may have figured out what the problem is. I do not know how to link properly using the command line. I've been doing:

1) prompt>qmake -project
2) then manually add the plugin info to the myproject.pro as shown in an earlier post
3) prompt>qmake
4) prompt>make

I guess I have to use -l in step 4?? How?
Thanks again

[jacek]

I guess I have to use -l in step 4?? How?

Actually make should do that for you. What is the last command it runs?

[ht1]

Hi Jacek,

The last command I run when I compile is
prompt> make
I don't know if that's what you meant when you asked about the last command?

The last thing the compiler does before giving error message is:
-LC:/Qt/4.3.3/plugins/imageformats/ -lqmng4 -lQtGui -ldgi32 -lcomdlg32 -loleaut32 -limm32 -lwinmm -lwinspool -lmsimg32 -lQtCore -lkernel32 -luser32 -lshell32 -luuid -lole32 -ladvapi32 -lws_32
(hopefully I didn't make mistakes copying it down)

[jacek]

I don't know if that's what you meant when you asked about the last command?

I asked you about the last command that make runs.

Run:

make > aaa.txt

After make finishes its job, open aaa.txt and find the line with lots of "-l<something>" (it should be near the end of that file) and post it here.

[ht1]

Hi again.

I didn't find the aaa.txt but
the last thing the compiler does before giving error message is:

-LC:/Qt/4.3.3/plugins/imageformats/ -lqmng4 -lQtGui -ldgi32 -lcomdlg32 -loleaut32 -limm32 -lwinmm -lwinspool -lmsimg32 -lQtCore -lkernel32 -luser32 -lshell32 -luuid -lole32 -ladvapi32 -lws_32

[ht1]

Jacek, you are asking a very good question about the compiler. The compiler says:

-LC:/Qt/4.3.3/plugins/imageformats/ -lqmng4 -lQtGui -ldgi32 -lcomdlg32 -loleaut32 -limm32 -lwinmm -lwinspool -lmsimg32 -lQtCore -lkernel32 -luser32 -lshell32 -luuid -lole32 -ladvapi32 -lws_32

but my working directory is Qt/static, not Qt/4.3.3. Seems like the system is confused about the folder where imageformat flugins are. What does that mean?

I just put the imageformat plugins in the folder that compiler wants. Now the error is:
"cannot find -lqjpeg4"

[jacek]

What does that mean?

It means that most likely you were using the wrong qmake.

Run:

make clean
C:\Qt\static\bin\qmake
make

[ht1]

Jacek, you are a genius! Thank you so much, your suggestion worked and now everything is perfect!

After two weeks of banging my head against the wall!

[vietdoor]

Hi all,

How to use and build the jpg plugin on QtCreator?

I got the error = undefined reference to `qt_plugin_instance_qjpeg()'

[guitronic]

Hi all,

How to use and build the jpg plugin on QtCreator?

I got the error = undefined reference to `qt_plugin_instance_qjpeg()'

Hi all
try use Q_IMPORT_PLUGIN(QJPEGPlugin) for Qt 5.0.2 is good