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POQt signaling across threads, one is GUI thread?
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copied!<p>What does it mean to move a object from one thread to another in Qt using moveToThread? Everything seems to work even before using moveToThread, which moves the object from one thread (GUI thread) to a another thread ( worked) and Qt:connect calls the appropriate slot on object.</p> <p>Is there any difference because of where the object lives, GUI thread or the worker thread?</p> <p>EDIT: I made a small program, but I don't understand how QThread works along with Signal and slot function, I would appreciate if you could explain what is the use of moveToThread with the example</p> <pre><code>#include <QtGui/QApplication> #include <QPushButton> #include <QHBoxLayout> #include <QLineEdit> #include <QString> #include "mythread.h" //GUI calls a thread to do some job and sub update the text box once it is done int main(int argc, char *argv[]) { QApplication a(argc, argv); QWidget w; QHBoxLayout * pH = new QHBoxLayout(&w); QPushButton * pushButton = new QPushButton("asdad"); QLineEdit * lineEdit = new QLineEdit("AAA"); pH->addWidget(pushButton); pH->addWidget(lineEdit); w.setLayout(pH); w.show(); MyThread thread; qDebug("Thread id %d",(int)QThread::currentThreadId()); QObject::connect(pushButton,SIGNAL(clicked()),&thread,SLOT(callRun())) ; QObject::connect(&thread,SIGNAL(signalGUI(QString)),lineEdit,SLOT(setText(QString))); return a.exec(); } #ifndef MYTHREAD_H #define MYTHREAD_H #include <QThread> #include <QMutex> class MyThread : public QThread { Q_OBJECT public: MyThread(); public slots: void callRun(); void run(); signals: void signalGUI(QString); private: QMutex mutex; }; #endif // MYTHREAD_H #include "mythread.h" #include <QDebug> #include <QString> #include <QMutexLocker> MyThread::MyThread() { } void MyThread::callRun() { qDebug("in thread"); if(!isRunning()) { this->start(LowestPriority); exec(); } else { run(); } } void MyThread::run() { QMutexLocker fn_scope(&mutex); static int a = 0; ++a; qDebug("Thread id inside run %d",(int)QThread::currentThreadId()); this->sleep(3); static QString number; QString temp; number += temp.setNum(a); emit signalGUI(number); } </code></pre>

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