Problem with Executing Example [SOLVED]

[SidRama]

I have installed QT from source and everything seems fine. This is the test code I am trying to run:

#include <QApplication>
#include <QTextEdit>

    int main(int argv, char **args)
    {
        QApplication app(argv, args);

        QTextEdit textEdit;
        textEdit.show();

        return app.exec();
   }

I saved this in a folder called QTCode. I then used qmake -project and qmake. However, when I finally call make I get the following error:

g++ -Wl,-O1 -Wl,-rpath,/usr/local/Qt-5.4.1/lib -o QTCode test.o -L/usr/local/Qt-5.4.1/lib -lQt5Gui -lQt5Core -lGL -lpthread
test.o: In function main': test.cpp:(.text.startup+0x27): undefined reference toQApplication::QApplication(int&, char**, int)'
test.cpp:(.text.startup+0x31): undefined reference to QTextEdit::QTextEdit(QWidget*)' test.cpp:(.text.startup+0x39): undefined reference toQWidget::show()'
test.cpp:(.text.startup+0x3e): undefined reference to QApplication::exec()' test.cpp:(.text.startup+0x49): undefined reference toQTextEdit::~QTextEdit()'
test.cpp:(.text.startup+0x51): undefined reference to QApplication::~QApplication()' test.cpp:(.text.startup+0x68): undefined reference toQApplication::~QApplication()'
test.cpp:(.text.startup+0x7b): undefined reference to `QTextEdit::~QTextEdit()'
collect2: error: ld returned 1 exit status
make: *** [QTCode] Error 1

I am not sure if this is a problem with installation. I would be grateful for any help! Thank you!

[koahnig]

@SidRama
Hi and welcome to devnet

There is actually an example for QTextEdit available.

What do you have in your .pro file?

[SidRama]

Hi!
Actually, the above program is from an example:
http://doc.qt.io/qt-4.8/gettingstartedqt.html

This is the contents of the .pro file:

TEMPLATE = app
TARGET = QTCode
INCLUDEPATH += .
#Input
SOURCES += test.cpp

In the folder I have a Makefile, a QTCode.pro file, test.cpp and test.o

Thank you!

[koahnig]

@SidRama
You should use the new example. There are only a couple of differences between Qt4 and Qt5. However, a major difference is probably in the .pro file. That may explain your problem.

[SGaist]

Hi and welcome to devnet,

@koahnig is right, with Qt 5, the widgets have now their own module separated from gui, so the pro files from Qt 4 won't have QT += widgets that is needed to compile with Qt 5.

[SidRama]

Hi!
Thank you so much! It turns out that I hadn't installed QT properly and the CLASSPATH was messed up.