#include <QtCore/QCoreApplication>#include <QtGui/QLabel>int main(int argc, char *argv[]){QCoreApplication a(argc, argv);QLabel label("Hello world");label.show();return a.exec();}I am using QTCreator, I installed QT 4.7 on windows.Now every time I compile I get this error:
:: error: collect2: ld returned 1 exit statusWith mingw32 giving me the followingtmp/obj/debug_shared/main.o: In function `main': E:\Qt\2010.04\qt\QTHello-build-desktop/../QTHello/main.cpp:6: undefined reference to `_imp___ZN6QLabelC1ERK7QStringP7QWidget6QFlagsIN2Qt10WindowTypeEE' E:\Qt\2010.04\qt\QTHello-build-desktop/../QTHello/main.cpp:8: undefined reference to `_imp___ZN6QLabelD1Ev' E:\Qt\2010.04\qt\QTHello-build-desktop/../QTHello/main.cpp:8: undefined reference to `_imp___ZN6QLabelD1Ev' collect2: ld returned 1 exit status mingw32-make[1]: *** [debug\QTHello.exe] Error 1 mingw32-make: *** [debug-all] Error 2 The process "E:/Qt/2010.04/mingw/bin/mingw32-make.exe" exited with code %2.Error while building project QTHello (target: Desktop)When executing build step 'Make'Whats the problem??
Best Answer
Create a Qt GUI project and olny then write what you have written.
Your project file is probably not including the required stuff. Do you have either
TEMPLATE = appor
QT += guiin your .pro file?
Are you linking with QtGui? If you don't, do it.
Also, for UI applications you must use QApplication. QCoreApplication is for CLI-only tools.
You want to create a Hello World app with QT? Really simple:
- Create a new GUI app into QtCreator
- Open the ui file and add a label using the QtDesigner embedded into QtCreator
- Compile and launch
You have your Hello World application done with Qt
Then if you want to know how to write a QTGui application, just open files in project to see what is written in them.