使用Qthread-Qt5创建新线程

Question

我正在尝试创建一个新的线程gpsthread,它应该在后台运行,并存储该值.

class gpsthread: public QThread{
    Q_OBJECT
private:nrega_status_t status2;

public: 
explicit gpsthread(QObject *parent = 0):QThread(parent) {
    // QTimer *t = new QTimer(this);
    // connect(t, SIGNAL(timeout()), this, SLOT(processgps()));
    // t->start(10000);
 }
 void run(){
    qDebug()<<"inside gps thread\n";
    QTimer *t = new QTimer(this);
     connect(t, SIGNAL(timeout()), this, SLOT(processgps()));
     t->start(10000);
    }

public slots:void processgps(){
    int status2;
    status2=gps_management();
}
};

我的主要课程是quickview.

int main(int argc, char *argv[])
{

QString file = "qml/main.qml";
QApplication app(argc, argv);
TranslationTest myObj;
QuickView view;
subthread object;
gpsthread obj;
gprsthread gprs;
view.rootContext()->setContextProperty("rootItem", (QObject *)&myObj);

    obj.start();
//from subthread
QObject::connect(&object, SIGNAL(batterytoqml(QVariant,QVariant)),item, SLOT(frombattery(QVariant,QVariant)));
QObject::connect(&gprs, SIGNAL(gprstoqml(QVariant)),item, SLOT(fromgprs(QVariant)));
return app.exec();

}

我也尝试过这个

class gpsthread: public QThread{
    Q_OBJECT
private:nrega_status_t status2;

public:QTimer* t; 
explicit gpsthread(QObject *parent = 0):QThread(parent) {
    // QTimer *t = new QTimer(this);
    // connect(t, SIGNAL(timeout()), this, SLOT(processgps()));
    // t->start(10000);
 }
 void run(){
    qDebug()<<"inside gps thread\n";
    t = new QTimer(this);
     connect(t, SIGNAL(timeout()), this, SLOT(processgps()));
     t->start(10000);
exec();    
}

public slots:void processgps(){
    int status2;
    status2=gps_management();
}
};

但这是错误的说法

 QObject: Cannot create children for a parent that is in a different thread

如果我在构造函数中创建对象,那么它也会给出相同的错误,因为该对象将在主线程中创建.怎么解决这个？

Answer 1

不推荐使用QThread继承.QThread是一个运行事件循环的完整类,通常是您需要的.该文档建议使用从QObject继承并在插槽中工作的worker对象.工人被转移到QThread.发送连接信号时,插槽将以正确的线程运行.

class gpsworker: public QObject
{
Q_OBJECT
public:
    explicit gpsworker(QObject *parent = 0):
    QObject(parent)
    {}

public slots:
    void processgps() {
        qDebug() << "processgps()" << QThread::currentThreadId();
    }
}

void OwnerClass::startWorker() {
    QTimer *timer = new QTimer(this);
    QThread *thread = new QThread(this);
    this->worker = new gpsworker();
    this->worker->moveToThread(thread);
    connect(timer, SIGNAL(timeout()), this->worker, SLOT(processgps()) );
    connect(thread, SIGNAL(finished()), this->worker, SLOT(deleteLater()) );
    thread->start();
    timer->start();
}

如果你想让计时器也存在于另一个线程中,那么它QTimer::start就是一个插槽.