Hi all,

I wrote a simple program using Qt. The program is below.

#include <qapplication.h>
#include <qmainwindow.h>

int main(int argc, char **argv)
{
QApplication app(argc, argv);
QMainWindow window();
app.setMainWidget (window);
window.show();
return app.exec();
}

I compiled this program with following command.

g++ -o qt1 qt1.cpp -I$QTDIR/include -L$QTDIR/lib -lqt

When compiled with above commands i got the following error.

[root@localhost qt]# g++ -o qt1 qt1.cpp -I$QTDIR/include -L$QTDIR/lib -lqt
qt1.cpp: In function `int main(int, char**)':
qt1.cpp:8: error: no matching function for call to `QApplication::setMainWidget(QMainWindow (&)())'
/usr/lib/qt-3.3/include/qapplication.h:122: note: candidates are: virtual void QApplication::setMainWidget(QWidget*)
qt1.cpp:9: error: request for member `show' in `window', which is of non-class type `QMainWindow ()()'
[root@localhost qt]#


what might be the problem? Does any one has any idea?

when i typed "echo $QTDIR" i got
/usr/lib/qt-3.3

so any one has any solution?

Thanks in advance.

sateesh.

qt1.cpp:8: error: no matching function for call to `QApplication::setMainWidget(QMainWindow (&())'

This is telling you that there's no setMainWidget() method in QApplication that takes a QMainWindow object as a parameter.

QApplication::setMainWidget(QWidget*)

That line is telling you that setMainWidget() takes a pointer to a QWidget as an argument, so you need to pass the address of a QWidget object (or one of a class that is derived from it, like QButton, QLabel for example) to that method.

You should have the Qt documentation on your system. On my machine, it's located in /usr/lib/qt-3.3.3/doc (but it might be different on yours). Have a look at the tutorial and the other stuff there (such as the class references).