方法一：继承QThread老式方法

1.定义继承QThread的类A 复写run()函数;

2.在主线程中实例化A对象a

3.通过调用a->start()启动线程,线程会自动调用run()虚函数;run不可直接调用;

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QThread>

class myThread: public QThread
{
public:
    myThread();
    void run(); //声明继承于QThread虚函数 run()
};

#endif // MYTHREAD_H 
 

//mythread.cpp

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

myThread::myThread()
{

}
void myThread::run()
{
  qDebug() <<  "hello world!"; //复写QThread类的 run()函数
}
 

//main.cpp
#include <QCoreApplication>
#include "mythread.h"   //包涵头文件
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    myThread *thread1 = new myThread; //新建线程对象
    thread1->start();  //启动线程
 
    return a.exec();
}

方法二： 使用QT信号和槽的概念创建线程

1.创建继承Obeject的类A 将要在线程中实现的方法在A类中实现

2.在主线程中实例化A对象a,再实例化QThread类对象b

3.通过a.moveToThread(&b);将a对象的实现移入线程b对象作用范围内运行

4.b->start()启动线程;

5.通过信号与槽的方式启动调用A类成员函数;

// Worker 类定义 cpp
 #include <QtCore>  
    class Worker : public QObject  //对象a
    {  
        Q_OBJECT  
    private slots:  
        void onTimeout()  
        {  
            qDebug()<<"Worker::onTimeout get called from?: "<<QThread::currentThreadId();  
        }  
    };

//main函数cpp

   int main(int argc, char *argv[])  
    {  
        QCoreApplication a(argc, argv);  
        qDebug()<<"From main thread: "<<QThread::currentThreadId();  
       
        QThread t;  //对象b
        Worker worker;  
        worker.moveToThread(&t);  
        t.start();  

        connect(t,SIGNAL(started()),worker,SLOT(onTimeout()));

        return a.exec();  
    }