Thread: unable to get simple program working

Hi !

I'm new to C++ and Qt Programming. I just read a book about Qt and now i want starting my programmer carrer .

Okay, here is the code of my prog:

Code:

/* Just open simple qt-Window */
#include <qapplication.h>
#include <qlabel.h>

int main(int argc, char **argv) {
  QApplication *app = new QApplication(argc , argv);
  //QLabel *qLabel = new QLabel("<H1>Nettes Proggie<h1>", 0);
  //qLabel->show();
  //app->setMainWidget(qLabel);
  return app->exec();  
}
//finish

Very simple, isn't it?
Well i'm using a debian system and i installed the qt2 & qt3 dev-libs via apt-get. They can be found in /usr/inlcude/qt & /usr/include/qt3. I also modified the /etc/ld.so.conf with the apropreate(?) paths and ran ldconfig.
Then I try to compile my prog with the command:

Code:

tom@debian:~/eigene dateien/Programmieren/qt-kde Programmierung$ g++ -o prog1 -I /usr/include/qt -lqt prog1.cpp
/tmp/ccyTUIn6.o(.text+0x32): In function `main':
: undefined reference to `QApplication::QApplication[in-charge](int&, char**)'
/tmp/ccyTUIn6.o(.text+0x8e): In function `main':
: undefined reference to `QApplication::exec()'
collect2: ld returned 1 exit status

Unfortunately it doesn't work an i do not understand the compiler's output, since i haven't much experience using the gcc.

I appreciate any suggestions.

thx
tom

Hi folks !

I got it.

If the compiler's output is something like:

Code:

: undefined reference to `QApplication::QApplication[in-charge](int&, char**)'

then it's just that two libs (for example qt2 & qt3) are conflicting.

The solution is very simple: just remove one of the two libs.

Now it should work.

greetings
tom