从QThread继承方式

1. qdicethread.h

#ifndef QDICETHREAD_H
#define QDICETHREAD_H

#include <QObject>
#include <QThread>

class QDiceThread : public QThread
{
    Q_OBJECT
public:
    explicit QDiceThread(QThread *parent = nullptr);
    void diceBegin();
    void dicePause();
    void stopThread();

private:
    int m_seq = 0;
    int m_diceValue;
    bool m_Paused = true;
    bool m_stop = false;

    // QThread interface
protected:
    virtual void run() override;

signals:
    void newValue(int seq, int diceValue);


};

#endif // QDICETHREAD_H

2. qdicethread.cpp

#include "qdicethread.h"
#include <QTime>

QDiceThread::QDiceThread(QThread *parent)
    : QThread{parent}
{

}

void QDiceThread::diceBegin()
{
    //开始掷骰子
    m_Paused = false;
}

void QDiceThread::dicePause()
{
    //暂停掷骰子
    m_Paused = true;
}

void QDiceThread::stopThread()
{
    //停止线程
    m_stop = true;
}

void QDiceThread::run()
{
    //线程任务
    m_stop = false;
    m_seq = 0;

    //随机数初始化，qsrand是线程安全的
    qsrand(QTime::currentTime().msec());

    //循环主体
    while(!m_stop)
    {
        if(!m_Paused)
        {
            m_diceValue = qrand();
            m_diceValue = (m_diceValue % 6) + 1;
            m_seq++;

            //发送信号
            emit newValue(m_seq, m_diceValue);
        }

        //现场休眠500ms
        msleep(500);
    }

    //相当与exit(0), 退出线程的事件循环
    quit();
}

3. dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QWidget>
#include <QDialog>
#include "qdicethread.h"

QT_BEGIN_NAMESPACE
namespace Ui { class Dialog; }
QT_END_NAMESPACE

class Dialog : public QDialog
{
    Q_OBJECT

public:
    Dialog(QWidget *parent = nullptr);
    ~Dialog();

private:
    Ui::Dialog *ui;

private:
    QDiceThread threadA;

protected:
    virtual void closeEvent(QCloseEvent *event) override;

private slots:
    void onThreadA_started();
    void onThreadA_finished();
    void onThreadA_newValue(int seq, int diceValue);
    void on_pushButton_startThread_clicked();
    void on_pushButton_stopThread_clicked();
    void on_pushButton_start_clicked();
    void on_pushButton_pause_clicked();
    void on_pushButton_clear_clicked();
};
#endif // DIALOG_H

4. dialog.cpp

#include "dialog.h"
#include "ui_dialog.h"
#include <QCloseEvent>

Dialog::Dialog(QWidget *parent)
    : QDialog(parent)
    , ui(new Ui::Dialog)
{
    ui->setupUi(this);

    //信号连接
    connect(&threadA, SIGNAL(started()), this, SLOT(onThreadA_started()));
    connect(&threadA, SIGNAL(finished()), this, SLOT(onThreadA_finished()));
    connect(&threadA, SIGNAL(newValue(int, int)), this, SLOT(onThreadA_newValue(int, int)));
}

Dialog::~Dialog()
{
}

void Dialog::closeEvent(QCloseEvent *event)
{
    //窗口关闭事件，必须结束线程
    if(threadA.isRunning())
    {
        threadA.stopThread();
        threadA.wait();
    }
    event->accept();
}

void Dialog::onThreadA_started()
{
    //状态
    ui->label_status->setText("Thread状态： thread started");
}

void Dialog::onThreadA_finished()
{
    //状态
    ui->label_status->setText("Thread状态： thread finished");
}

void Dialog::onThreadA_newValue(int seq, int diceValue)
{
    QString str = QString::asprintf("第 %d 次掷骰子，点数为： %d\r\n", seq, diceValue);
    ui->textEdit->append(str);

    ui->label_num->setText(QString("%1").arg(diceValue));
}


void Dialog::on_pushButton_startThread_clicked()
{
    //启动线程
    threadA.start();

    ui->pushButton_start->setEnabled(false);
    ui->pushButton_stopThread->setEnabled(true);
    ui->pushButton_start->setEnabled(true);
    ui->pushButton_pause->setEnabled(false);
}


void Dialog::on_pushButton_stopThread_clicked()
{
    //结束线程
    threadA.stopThread();
    threadA.wait();

    ui->pushButton_start->setEnabled(true);
    ui->pushButton_stopThread->setEnabled(false);
    ui->pushButton_start->setEnabled(false);
    ui->pushButton_pause->setEnabled(false);
}


void Dialog::on_pushButton_start_clicked()
{
    //开始掷骰子
    threadA.diceBegin();

    ui->pushButton_start->setEnabled(false);
    ui->pushButton_pause->setEnabled(true);
}


void Dialog::on_pushButton_pause_clicked()
{
    //暂停掷骰子
    threadA.dicePause();

    ui->pushButton_start->setEnabled(true);
    ui->pushButton_pause->setEnabled(false);
}


void Dialog::on_pushButton_clear_clicked()
{
    ui->textEdit->clear();
}

5. 效果