[C++知识库]Qt使用线程的两种方法

方法一：使用QThread类
继承QThread类，覆写run函数，使用run方法启动线程，使用wait方法等待线程退出
例子：
mythread.h

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QThread>
#include<QDebug>


class myThread : public QThread
{
    Q_OBJECT
public:
    explicit myThread(int threadId,QObject *parent = 0);
    void run();
    int threadId;
signals:
    
public slots:
    
};

#endif // MYTHREAD_H

mythread.cpp

#include "mythread.h"

myThread::myThread(int threadId,QObject *parent) :
    threadId(threadId),
    QThread(parent)
{
}
void myThread::run(){
    for(int i=0;i<5;i++){
        QThread::msleep(100);

        qDebug()<<"Thread "<<threadId<<" is running,i="<<i;

    }
}

main.cpp

#include <QCoreApplication>
#include <mythread.h>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    myThread mt(1);
    myThread mt1(2);
    mt.start();
    mt1.start();
    mt.wait();
    mt1.wait();
    return a.exec();
}

运行结果：

方法二：使用QRunnable
继承QRunnable类，覆写run方法，使用QThreadPool的start方法启动线程，使用waitForDone方法等待线程退出
例子：
mythread.h

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QRunnable>
#include<QThread>
#include<QDebug>

class myThread : public QRunnable
{
    //Q_OBJECT 不是QObject的子类，不需要定义Q_OBJECT
public:
    explicit myThread(int threadId,QObject *parent = 0);
    void run();
    int threadId;
signals:
    
public slots:
    
};

#endif // MYTHREAD_H

mythread.cpp

#include "mythread.h"

myThread::myThread(int threadId,QObject *parent) :
    threadId(threadId)
{
}
void myThread::run(){
    for(int i=0;i<5;i++){
        QThread::msleep(100);

        qDebug()<<"Thread "<<threadId<<" is running,i="<<i;

    }
}

main.cpp

#include <QCoreApplication>
#include<mythread.h>
#include<QThreadPool>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    myThread *mt=new myThread(1);
    myThread *mt1=new myThread(2);
    QThreadPool tp;
    tp.start(mt);
    tp.start(mt1);
    tp.waitForDone();
    return a.exec();
}

运行结果：