Qmake

BrajZore · 08-19-2009, 01:21 PM

Hi everyone!

I'm trying to learn QT and now I have a problem with qmake.

I create a project file with this command: qmake -project

My QT.pro looks like this:

Code:

######################################################################
# Automatically generated by qmake (1.07a) Wed Aug 19 21:33:54 2009
######################################################################

TEMPLATE = app
CONFIG += qt warn_on release 
INCLUDEPATH += .
TARGET = hello_world
SOURCES += hello_world.cpp

To get a makefile, i use this command: qmake -o Makefile QT.pro

When I type in make, this message appears:

Code:

g++ -c -pipe -Wall -W -O2  -DQT_NO_DEBUG -DQT_SHARED -DQT_THREAD_SUPPORT -I/usr/lib/qt/mkspecs/default -I. -I. -I/usr/lib/qt/include -o hello_world.o hello_world.cpp
hello_world.cpp:1:24: error: QApplication: No such file or directory
hello_world.cpp:2:18: error: QLabel: No such file or directory
hello_world.cpp: In function 'int main()':
hello_world.cpp:6: error: 'QApplication' was not declared in this scope
hello_world.cpp:6: error: expected `;' before 'a'
hello_world.cpp:8: error: 'QLabel' was not declared in this scope
hello_world.cpp:8: error: expected `;' before 'label'
hello_world.cpp:9: error: 'label' was not declared in this scope
hello_world.cpp:11: error: 'a' was not declared in this scope
make: *** [hello_world.o] Error 1

I don't know what the problem is. How can I compile and run the programs created in QT in a efficient way?

orgcandman · 08-19-2009, 01:27 PM

Quote:

hello_world.cpp:1:24: error: QApplication: No such file or directory
hello_world.cpp:2:18: error: QLabel: No such file or directory
hello_world.cpp: In function 'int main()':
hello_world.cpp:6: error: 'QApplication' was not declared in this scope
hello_world.cpp:6: error: expected `;' before 'a'
hello_world.cpp:8: error: 'QLabel' was not declared in this scope
hello_world.cpp:8: error: expected `;' before 'label'
hello_world.cpp:9: error: 'label' was not declared in this scope
hello_world.cpp:11: error: 'a' was not declared in this scope

This indicates there could be a problem with your source. Can you post? Make sure to use code tags.

BrajZore · 08-19-2009, 02:03 PM

Quote:

Originally Posted by orgcandman

This indicates there could be a problem with your source. Can you post? Make sure to use code tags.

hello_world.cpp

PHP Code:



#include <QApplication> 
#include <QLabel> 
 
int main() 
{ 
    QApplication a(argc, argv); 
     
    QLabel label("Hello world"); 
    label.show(); 
     
    return a.exec(); 
}

xhypno · 08-19-2009, 03:02 PM

Verify that your include path is correct.

your using /usr/lib/qt/include but it appears to not be finding the QT classes under it.

knudfl · 08-19-2009, 08:43 PM

The real name of the qt4 headers :
QtGui/QApplication and QtGui/QLabel
> >
#include <QtGui/QApplication>
#include <QtGui/QLabel>

The Qt4 headers are grouped in 19 directories :
//include/QtXxxx/<headers>

Ref. for qmake
http://doc.trolltech.com/3.0/qmake-guide.html
" qmake User's Guide "

The command 'qmake --help' is useful too.
.....

The file QT.pro can be very simple, ( 2 lines ) :
SOURCES = hello_world.cpp
TARGET = hello_world

'-Makefile' is default for qmake, so this will do
'qmake QT.pro'
to create the Makefile.
.....

BrajZore · 08-21-2009, 10:44 AM

Quote:

Originally Posted by xhypno

Verify that your include path is correct.

your using /usr/lib/qt/include but it appears to not be finding the QT classes under it.

How can I verify it?

How can I do so the classes can be find?

xhypno · 08-21-2009, 11:09 AM

Quote:

Originally Posted by BrajZore

How can I verify it?

How can I do so the classes can be find?

It depends on the os that you have installed. On Juanty with qt4 installed via apt the includes are here:

/usr/include/qt4/

Here is an update fixing issues with your cpp file (the input vars from the command line) and the compile output from my system.

Code:

#include <QApplication>
#include <QLabel>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    
    QLabel label("Hello world");
    label.show();
    
    return a.exec();
}

Code:

g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -I. -o hello_world.o hello_world.cpp
g++ -Wl,-O1 -o hello_world hello_world.o    -L/usr/lib -lQtGui -lQtCore -lpthread

This compile works fine on my system. If your include paths and lib paths are still wrong you can set them with the following in your project file.

Code:

INCLUDEPATH += <dir>
LIBRARYPATH += <dir>

BrajZore · 08-26-2009, 01:51 AM

Quote:

Originally Posted by xhypno

It depends on the os that you have installed. On Juanty with qt4 installed via apt the includes are here:

/usr/include/qt4/

Here is an update fixing issues with your cpp file (the input vars from the command line) and the compile output from my system.

Code:

#include <QApplication>
#include <QLabel>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    
    QLabel label("Hello world");
    label.show();
    
    return a.exec();
}

Code:

g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -I. -o hello_world.o hello_world.cpp
g++ -Wl,-O1 -o hello_world hello_world.o    -L/usr/lib -lQtGui -lQtCore -lpthread

This compile works fine on my system. If your include paths and lib paths are still wrong you can set them with the following in your project file.

Code:

INCLUDEPATH += <dir>
LIBRARYPATH += <dir>

Hi!

It doesen't work. I still get the message:

Code:

hello_world.cpp:1:24: error: QApplication: No such file or directory
hello_world.cpp:2:18: error: QLabel: No such file or directory
hello_world.cpp: In function 'int main(int, char**)':
hello_world.cpp:6: error: 'QApplication' was not declared in this scope
hello_world.cpp:6: error: expected `;' before 'a'
hello_world.cpp:8: error: 'QLabel' was not declared in this scope
hello_world.cpp:8: error: expected `;' before 'label'
hello_world.cpp:9: error: 'label' was not declared in this scope
hello_world.cpp:11: error: 'a' was not declared in this scope
hello_world.cpp: At global scope:
hello_world.cpp:4: warning: unused parameter 'argc'
hello_world.cpp:4: warning: unused parameter 'argv'

How can I compile a application SIMPLE in QT? When I used Ubuntu, I compiled my application, by going to the menu. But that option doesen't exists QT on Slackware system. Why?

graemef · 08-26-2009, 04:31 AM

I don't think that you are picking up the qt4 library, rather I suspect that you are picking up the code in the qt3 library. You may need to add this path to your $PATH variable.

graemef · 08-26-2009, 04:32 AM

Quote:

Originally Posted by BrajZore

When I used Ubuntu, I compiled my application, by going to the menu. But that option doesen't exists QT on Slackware system. Why?

Have you installed the QT Creator? Just one IDE that you can use to easily compile Qt applications.