3rd Party Software

The error has nothing to do with Qt. Qt is a library, the error is coming from your compiler or linker.

You probably need something like:

@INCLUDEPATH += -I{{path_to_stk}}/include/stk
LIBS += -L{{path_to_stk}}/lib -lstk
@

in your PRO file. Substitute suitable values for {{path_to_stk}} they depend on your platform and install directories.

Thank you messi.

I have figured out how to do it now. It was a problem with stylesheet and QPalette.

Just a note, if you want to set the background color of the plot use:

@Plot->canvas()->setStyleSheet(" QwtPlotCanvas { background-color: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0 #f6f7fa, stop: 1 #dadbde); }");@

Then to change the border around the plot (including the axes and such) use:
@Plot->setStyleSheet(" QwtPlot { background-color: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0 #f6f7fa, stop: 1 #dadbde); }");@

Thanks again.

Hello ultrasurf,

after a lot of search and testing I finally managed to get breakpad working on all platforms. I wrote step-by-step article with examples how to do it.

"http://blog.inventic.eu/2012/08/qt-and-google-breakpad/":http://blog.inventic.eu/2012/08/qt-and-google-breakpad/

Yes it may be a problem with my setup. I am writing an application on Windows XP and Linux using Qt 4.8.1 and I am having different problems with each. The above problem with Linux and the, ‘SerialPort’ was not declared in this scope, problem with moc_serialport.cpp that was reported earlier. I have tried manually making the library as you suggested earlier and also using QtCreator with the same result.

I have also tried compiling on XP using MinGW and on Linux using MinGW with the same result. Still working on it.

I have updated the title to reflect both the wrong and the correct spelling. ust in case someone has the same problem.
Furthermore, the link in the second post has been fixed.

Have you checkout the qwt docs:
http://qwt.sourceforge.net/class_qwt_plot.html#adb0b2e68d86039f86e3240fb399fa0fe

Using canvas()->setPalette() is a more powerful way to set these colors.

or you can make a test with stylesheet technik, like:
QwtPlot::setStyleSheet(" QwtPlot {background-color: #FF0000}");

[quote author="simplePlan" date="1345041060"]I today had the same error. I fixed it by switching to release mode. Seems like I only got the libraries for the release version (using Windows 7 64 bit, Qt Designer using MSVC 2010 compiler).[/quote]

Worked for me. Thank you!

Ffmpeg would help for you.

[quote author="Lukas Geyer" date="1344578162"]Well, QtCreator is open-source and plugin-based. Feel free to start hacking on you own designer backend which allows for generating Wt code instead of Qt code.
[/quote]

How can I create a Plugin for Qt. Is there any tutorial to do that?

[quote author="Lukas Geyer" date="1344578162"]
In addition, if it is just about pushing your application to the web be aware that Qt has a "native client resp. HTML5 backend":http://www.youtube.com/watch?v=qDyWjNju1yU (but don't ask me about the maturity).[/quote]

Where can I find a tutorial for learning HTML5

qtcentre.org forum has sub-forum Qwt. It's maintained by developer of Qwt.

I am happy for help you. :)

QX11EmbedContainer seems to be only available for linux but I am trying to stay on a Windows platform for this project.

Do you know of an equivalent QX11EmbedContainer class for win 7?

i successed to compile the mysql driver for qt4.8.1 with mingw and it work for me very good ^^, i hope for you too.
this a link to the qsqlmysql4.qll, qsqlmysqld4.qll, http://www.mediafire.com/download.php?z1e1ypqhqc96icn.
just to tell you, i compile under windows 7 64 bits, mysql-5.5.25a-win32.
after downloading this two dll files copy them to you sqldrivers folder (for me is :C:\QtSDK\Desktop\Qt\4.8.1\mingw\plugins\sqldrivers) then copy the libsql.dll ( you find it in your mysql's lib directory for me is : C:\MYSQL\lib), and paste it in your project directory, and it will work , well i hope so because it work for me like this ^^

I execute the compiled app with root user and then works the open method()!

Can I make this works with a normal user?

[quote author="Volker" date="1342122841"]What are the actual error messages? Are they from the compiler or the linker?[/quote]

I think they are from compiler here is an example:
@g++ -Wl,-O1 -o Simulador_de_Particulas main.o janelaprincipal.o opengl.o trackball.o fastareader.o clusterclass.o moc_janelaprincipal.o moc_opengl.o qrc_shader.o -L/usr/lib -L/usr/X11R6/lib -lQtOpenGL -lQtGui -lQtCore -lGLU -lGL -lpthread
janelaprincipal.o: In function stPage::GetPageSize()': janelaprincipal.cpp:(.text+0x0): multiple definition of stPage::GetPageSize()'
main.o:main.cpp:(.text+0x0): first defined here
janelaprincipal.o: In function stPage::GetData()': janelaprincipal.cpp:(.text+0x10): multiple definition of stPage::GetData()'
main.o:main.cpp:(.text+0x10): first defined here
janelaprincipal.o: In function stLockablePage::GetPageSize()': janelaprincipal.cpp:(.text+0x20): multiple definition of stLockablePage::GetPageSize()'
main.o:main.cpp:(.text+0x20): first defined here
janelaprincipal.o: In function stLockablePage::GetData()': janelaprincipal.cpp:(.text+0x30): multiple definition of stLockablePage::GetData()'
main.o:main.cpp:(.text+0x30): first defined here@

and they continue for thousands of lines...

If you want to see all messages, I uploaded the output from make on my server: http://tiago.eti.br/make_output