Sample... You may adapt it to make calls from static functions, but I don't think that it is necesary. It is good practice to work with threads in next way: You should create your dialog in GUI thread and connect it's exec() slot to your signal with Qt::BlockingQueuedConnection
Worker.h
#include <QObject>
class Worker
: public QObject
{
Q_OBJECT
signals:
void showDialog();
public:
Worker( QObject *parent = NULL );
~Worker();
public slots:
void doLongWork();
private:
};
Worker.cpp
#include <QThread>
#include <QMessageBox>
#include <QDebug>
#include <QCoreApplication>
#include <Windows.h>
Worker::Worker( QObject *parent )
: QObject( parent )
{
}
Worker::~Worker()
{
}
void Worker::doLongWork() // You may override QThread::run with same effect, but it is bad practice
{
qDebug() << "Worker thread id = " << QThread::currentThreadId();
::MessageBoxA( NULL, "Click to show dialog in 3 seconds", NULL, 0 );
::Sleep( 3000 );
emit showDialog(); // "Showing" dialog from non-GUI thread. And wait for close
::MessageBoxA( NULL, "Dialog closed!", NULL, 0 );
qApp->quit();
}
main.cpp
#include <QApplication>
#include <QDialog>
#include <QThread>
#include <QDebug>
#include "Worker.h"
int main(int argc, char *argv[])
{
QApplication a( argc, argv );
a.setQuitOnLastWindowClosed( false );
QDialog dlg;
QThread workerThread;
Worker worker;
qDebug() << "Main thread id = " << QThread::currentThreadId();
QObject::connect( &workerThread, SIGNAL( started() ), &worker, SLOT( doLongWork() ) );
QObject::connect( &worker, SIGNAL( showDialog() ), &dlg, SLOT( exec() ), Qt::BlockingQueuedConnection ); // !!!See connection type!!!
worker.moveToThread( &workerThread );
workerThread.start();
return a.exec();
}
Note: WinAPI MessageBoxes are used only to visualize that thread is really waiting for close of dialog.