QThread tutorial part 2－天天向上

This time we are going to create a new Object intead of using subclass of QThread,

and all its job is transfer to a QThread instance by calling moveToThread method.

You can find out details on youtube.

Let’s create a new project of window application and add new class, in which it accumaltes from 1 to 999.

This is what it looks like after setting up previous settings.

1. Two heards <QThread> and <QDebug> are added

2. A slot named “DoJob” takes responsibility of doing something.

3. A public method “DoSetup” is passing a reference to this thread that it will asign current job to be run in the thread.

4.NumberChanged is used to notify the GUI for displaying the current number

myobject.h

#ifndef MYOBJECT_H#define MYOBJECT_H #include <QObject>#include <QThread>#include <QDebug>#include <QMutex> class MyObject : public QObject{    Q_OBJECTpublic:    explicit MyObject(QObject *parent = nullptr);    void DoSetup(QThread &thread);    bool Stop;signals:    void NumberChanged(int number); public slots:    void DoJob();  }; #endif // MYOBJECT_H

myobject.cpp

#include "myobject.h" MyObject::MyObject(QObject *parent) : QObject(parent){ } void MyObject::DoSetup(QThread &thread){    // connect the slot named DoJob to a signal, which is emitted by another thread    connect(&thread, SIGNAL(started()), this, SLOT(DoJob()));    this->Stop = false;} void MyObject::DoJob(){    for(int i=0; i<1000; i++)    {         //        if ( QThread::currentThread()->isInterruptionRequested() )        //                     break;        QMutex mutex;        mutex.lock();        if(Stop)        {            break;        }        mutex.unlock();         emit NumberChanged(i);        this->thread()->msleep(10);     }}

    //myThread.quit();

dialog.cpp

When start button clicks, myObject put itself into anther thread by a method called moveToThread.

The job of myObject is going to run as soon as the thread get started.

#include "dialog.h"#include "ui_dialog.h"  Dialog::Dialog(QWidget *parent)    : QDialog(parent)    , ui(new Ui::Dialog){    ui->setupUi(this);    // myobject informs the GUI that the number has changed    connect(&myObject, SIGNAL(NumberChanged(int)), this, SLOT(on_NumberChanged(int)));} Dialog::~Dialog(){    delete ui;}  void Dialog::on_pushButton_Start_clicked(){    // This time we create a new Object intead of using subclass of QThread,    // and all its job is transfer to a QThread instance by calling moveToThread method    myObject.DoSetup(myThread);    myObject.moveToThread(&myThread);    myThread.start();} void Dialog::on_pushButton_Stop_clicked(){    myObject.Stop = true;    int retCode = 0;    myThread.exit(retCode);    //qDebug() << QString::number(retCode);} void Dialog::on_NumberChanged(int number){    ui->label_number->setText(QString::number(number));}