For non Qt code I am trying to call Qcoreapplication with help of another thread.

Here the code:
ApplicationThread.h

#pragma once #include <qthread.h> #include "squidstat_dll_global.h" #include <iostream> class SQUIDSTAT_DLLSHARED_EXPORT ApplicationThread:public QThread { void run(); }; class SQUIDSTAT_DLLSHARED_EXPORT ApplicationStarter : public QObject { Q_OBJECT public: ApplicationStarter(); ~ApplicationStarter(); public slots: void onStarted(); };

ApplicationThread.cpp

#include "ApplicationThread.h" #include "MainWindow.h" #include "qcoreapplication.h" namespace ToolThreadGlobal { static int argc = 1; static char* argv[] = { QString("SquidState.exe").toLocal8Bit().data(),NULL}; static QCoreApplication *coreApp = nullptr; static ApplicationThread *toolThread = nullptr; }; void ApplicationThread::run() { if (ToolThreadGlobal::coreApp){ std::cout << "\nApplicationThread: thread run method is call"; ToolThreadGlobal::coreApp->exec(); } } ApplicationStarter::ApplicationStarter() { if (ToolThreadGlobal::toolThread == nullptr) { std::cout << "\nApplicationstarter Constructor call"; ToolThreadGlobal::toolThread = new ApplicationThread(); connect(ToolThreadGlobal::toolThread, &ApplicationThread::started, this, &ApplicationStarter::onStarted, Qt::DirectConnection); ToolThreadGlobal::toolThread->start(); } } ApplicationStarter::~ApplicationStarter() { std::cout << "\nApplicationStarter:: destructor is called"; // Ensure that the thread and the QCoreApplication are cleanly shut down: ToolThreadGlobal::toolThread->quit(); ToolThreadGlobal::coreApp->quit(); ToolThreadGlobal::coreApp->deleteLater(); ToolThreadGlobal::coreApp = nullptr; ToolThreadGlobal::toolThread->terminate(); ToolThreadGlobal::toolThread->wait(); ToolThreadGlobal::toolThread->deleteLater(); ToolThreadGlobal::toolThread = nullptr; } void ApplicationStarter::onStarted() { std::cout << "\nApplicationStarter::signal received"; if (QCoreApplication::instance() == NULL) { std::cout << "\nApplicationStarter::call QcoreApplication"; ToolThreadGlobal::coreApp = new QCoreApplication(ToolThreadGlobal::argc, ToolThreadGlobal::argv); std::cout << "\nApplicationStarter::call worker"; MainWindow w; std::cout << "\nApplicationStarter::call before exe"; } }

SquidState.h

#pragma once #include "squidstat_dll_global.h" #include "ApplicationThread.h" #ifndef _SQUIDSTAT_H_ #define _SQUIDSTAT_H_ namespace AISquid { class SQUIDSTAT_DLLSHARED_EXPORT SquidStat { public: SquidStat(); ~SquidStat(); void startAPP(); void closeAPP(); }; } #endif // !_SQUIDSTAT_H_

SquidState.cpp

#include <stdlib.h> #include "SquidStat.h" #include "ApplicationThread.h" AISquid::SquidStat::SquidStat() { std::cout << "\nSquidStat: SquidStat class object is created"; }; AISquid::SquidStat::~SquidStat() { std::cout << "\nSquidStat: SquidStat class object is destriod "; }; void AISquid::SquidStat::startAPP() { }; void AISquid::SquidStat::closeAPP() { };

Testing My dll with help of below code.

tester.cpp

#include "SquidStat.h" #include "ApplicationThread.h" void main(int argc, char *argv[]) { ApplicationStarter start; AISquid::SquidStat obj; obj.startAPP(); return; }

OutPut of Tester:
0_1554857416616_285cd514-f416-4d15-817b-51334702ce84-image.png

What is wrong am I doing here? I am receiving call for slot onStarted(); once ApplicationStarter start; object is destroy.

Any suggestion would be more appreciable.

@SGaist Thank you inform about me QtSingleApplication class. I will modify code and use QtSingleApplication.

@ekkescorner Oh, OK, thanks.

I thought we could put this in the build settings:

QMAKE_TARGET_BUNDLE_PREFIX = org.ekkescorner
QMAKE_BUNDLE = c2g.qtws