QT多线程的使用

今天给大家介绍三种QT里面使用多线程的方法

1、继承QThread并且重写run方法来实现多线程

#ifndef MYQTHREAD_H
#define MYQTHREAD_H
#include <QMutex>
#include <QThread>
class myQThread : public QThread
{
public:
myQThread()
{
    _isRunning = false;
}
void run()
{
    while(true)
    {
        _mutex.lock();
        if(!_isRunning)
        {
            qDebug() << "myqthread" << QThread::currentThreadId();
        }else
        {
            _mutex.unlock();
            break;
        }
        _mutex.unlock();
        QThread::msleep(2000);
    }
    _isRunning = false;
}
void stop()
{
    _mutex.lock();
    _isRunning = true;
    _mutex.unlock();
    this->quit();
    this->wait();
}

    volatile bool _isRunning;
    QMutex _mutex;
};

#endif // MYQTHREAD_H

2、使用movetothread方法实现多线程，该类一定要继承QObject

#ifndef MYOBJECTTHREAD_H
#define MYOBJECTTHREAD_H

#include <QObject>

class myObjectThread : public QObject
{
    Q_OBJECT
public:
    explicit myObjectThread(QObject *parent = nullptr);

signals:

public slots:
    void showID();
};

#endif // MYOBJECTTHREAD_H

3、使用c++11的thread来实现多线程

#ifndef MYC11THREAD_H
#define MYC11THREAD_H


class myc11Thread
{
public:
    myc11Thread();

    void showc11ID(int i);
};

#endif // MYC11THREAD_H

4、来看一看这三种多线程如何使用

void showID(int i)
{
    qDebug() << "全局函数的现成ID" << QThread::currentThreadId() << "i:" << i;
}
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    //QThread重写runfangfa
    tmpmyqthread = new myQThread();
    tmpmyqthread->start();

    //用movetothread，但是这个类要继承object
    QThread *th = new QThread;
    tmpmyobject = new myObjectThread();
    //把tmpmyobject这个类的对象放到线程中
    tmpmyobject->moveToThread(th);
    //通过信号槽的方法，把槽函数运行在线程中
    connect(th,SIGNAL(started()),tmpmyobject,SLOT(showID()));
    th->start();

    //C11原始的thread把全局函数初始化到线程
    std::thread th1(showID,2);
    th1.detach();

    //C11原始thread把类的函数初始化到线程运行
    tmpmyc11 = new myc11Thread();
    std::thread th2(&myc11Thread::showc11ID,tmpmyc11,2);
    th2.detach();
    qDebug() << "mainThread:" << QThread::currentThreadId();
}

QT里面三种多线程介绍到这里