Qt::线程::继承QRunnable

继承QRunnable。和QThread使用一样，线程类继承于QRunnable。
重写run函数。和QThread一样，需要重写run函数，run是一个纯虚函数，必须重写。
使用QThreadPool启动线程

class PThreadRunnable : public QRunnable
{
public:
    explicit PThreadRunnable();
    ~PThreadRunnable();
    void run();
};

PThreadRunnable::PThreadRunnable()
{
}

PThreadRunnable::~PThreadRunnable()
{
    qDebug() << __FUNCTION__;
}

void PThreadRunnable::run()
{
    qDebug() << __FUNCTION__ << QThread::currentThreadId();
    QThread::msleep(1000);
}

 PThreadRunnable * subThread = new PThreadRunnable();
 QThreadPool * threadPool = new QThreadPool();
 threadPool->setMaxThreadCount(2);
 threadPool->start(subThread);

 threadPool->waitForDone();