QThread類提供了與平臺無關的執行緒。

QThread從run()函式執行。run()通過呼叫exec()來開啟事件迴圈，並在執行緒內執行一個Qt事件迴圈。

要建立一個執行緒，需要子類化QThread，並且重新實現run()函式。

#ifndef MYQTHREAD_H
#define MYQTHREAD_H

#include <QThread>
class myQThread : public QThread
{
    Q_OBJECT
public:
    explicit myQThread(QObject* parent = 0);
    void stop();
protected:
    void run();
private:
    volatile bool stopped;
};

#endif // MYQTHREAD_H
 

#include "myqthread.h"
#include <QDebug>

myQThread::myQThread(QObject* parent):
    QThread(parent)
{
    stopped = false;
}

void myQThread::run()
{
    qreal i = 0;
    while(!stopped)
    {
        qDebug()<<QString("in myQThread:%1").arg(i);
        msleep(1000);
        i++;
    }
    stopped = false;
}

void myQThread::stop()
{
    stopped = true;
}
 

void MainWindow::on_startButton_clicked()
{
    if(!thread.isRunning())
    {
        qDebug()<<"thread is not running";
    }
    thread.start();
    ui->stopButton->setEnabled(true);
    ui->startButton->setEnabled(false);
}


void MainWindow::on_stopButton_clicked()
{
    if(thread.isRunning())
    {
        qDebug()<<"thread is running";
        thread.stop();
        ui->stopButton->setEnabled(false);
        ui->startButton->setEnabled(true);
    }
}