Solved Cannot Compile Code...

[SweetOrange]

Hi!
I am back to C++ and Qt after some time and want to run the
code found in "C++ GUI Programming with Qt 4" book.
I have downloaded and installed Qt 5.11.1 for x86, and MINGW 32-bit.

I get these errors when runing the code:

These are my debug settings:

Here is the code:

#include <QCoreApplication>
#include <QtWidgets/QLabel>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QLabel *label = new QLabel("Hello Qt!");
    label->show();

    return a.exec();
}

[mrjj]

Hi
Most likely the pro file is old.
make sure you have
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

[SGaist]

Hi,

In addition to the correct answer of @mrjj, your application won’t work. You need a QApplication if you want to use widgets.

[mrjj]

Just as a note
You can find updated version of the code here
https://github.com/mutse/qt5-book-code
That should be easier to use in Qt5

[SweetOrange]

@mrjj

Hi. I have placed

QT += widgets

at the second line of .pro file.

Now code compiles ok but as SGaist mentioned I need a QApplication.

Here is my corrected code:

[mrjj]

Super.
There is some difference with the includes between 4 and 5.