How to quit Application immedialy after QMessageBox?

king558

I would like detect current running Windows Version, if it is Windows Server then close application immedialy, qApp->exit(); does not seem have effect here.

#include "mainwindow.h"

#include <QApplication>

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include <QMessageBox>
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    if ( QSysInfo::prettyProductName().contains( "Server" ) ) {
        QMessageBox::information( Q_NULLPTR, "Test Mode", "It is : " + QSysInfo::prettyProductName() );      // Windows 10
        qApp->exit();
    }
}

MainWindow::~MainWindow()
{
    delete ui;
}

mpergand

@king558
You try to quit while your app even doesn't start.
try instead:

QMetaObject::invokeMethod(qApp, "quit",Qt::QueuedConnection);

Chris Kawa

Or just don't put that check code in the main window constructor and structure your app better. It doesn't look like it has anything to do with that window, so why is it in it, i.e.

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);

    if ( QSysInfo::prettyProductName().contains( "Server" ) ) {
        QMessageBox::information( Q_NULLPTR, "Test Mode", "It is : " + QSysInfo::prettyProductName() );      // Windows 10
        return 0;
    }

    MainWindow w;
    w.show();
    return a.exec();
}

king558

@mpergand

thx, it works good.

king558

@Chris-Kawa

Nice tipps, thx, I just began this way, forgot to put QApplication to first line