我看到这样的话题已经讨论了很多次,但是找不到简单情况的明确答案。我在自己的线程中运行Worker类,在该线程中创建计时器,并由于某种情况希望将其停止。但是我得到了错误:
无法从另一个线程停止计时器
我填补了在Qt中工作的线程缺少一些核心逻辑的情况。有人可以解释如何解决吗?谢谢。
这里是main.cpp
#include <QCoreApplication>
#include <QObject>
#include <QtDebug>
#include "worker.h"
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
Worker w;
return a.exec();
}
Worker.h
#ifndef WORKER_H
#define WORKER_H
#include <QObject>
#include <QTimer>
#include <QThread>
#include <QtDebug>
class Worker : public QObject
{
Q_OBJECT
public:
explicit Worker(QObject *parent = nullptr);
private:
QThread t;
QTimer *timer;
int count = 1;
public slots:
void dataTimerFunction();
void onStopTimer(QTimer *t);
signals:
void stopTimer(QTimer *t);
};
#endif // WORKER_H
Worker.cpp
#include "worker.h"
Worker::Worker(QObject *parent) : QObject(parent)
{
this->moveToThread(&t);
QObject::connect(&t, &QThread::finished, this, &QObject::deleteLater);
t.start();
// are we in the new thread from this point, right?
timer = new QTimer();
QObject::connect(timer, &QTimer::timeout, this, &Worker::dataTimerFunction);
QObject::connect(this, &Worker::stopTimer, this, &Worker::onStopTimer);
// QObject::connect(this, &Worker::stopTimer, this, &Worker::onStopTimer, Qt::QueuedConnection); doesn't work as well
timer->start(200);
}
void Worker::dataTimerFunction()
{
qDebug()<<count;
count++;
if (count>5){
emit stopTimer(timer);
//timer->stop();
}
}
void Worker::onStopTimer(QTimer *t)
{
t->stop();
}
问题确实是计时器未移至您的线程。
这里是经过修改的工作者类,可以完成您想要实现的目标。它将计时器也移动到线程,然后通过使用信号/插槽启动和停止它。
worker.h
#ifndef WORKER_H
#define WORKER_H
#include <QObject>
#include <QTimer>
#include <QThread>
#include <QtDebug>
class Worker : public QObject
{
Q_OBJECT
public:
explicit Worker(QObject *parent = nullptr);
private:
QThread t;
QTimer *timer;
int count = 1;
signals:
void stopTimer();
void startTimer(int msec);
public slots:
void dataTimerFunction();
};
#endif // WORKER_H
worker.cpp
#include "worker.h"
Worker::Worker(QObject *parent) : QObject(parent)
{
// are we in the new thread from this point, right?
timer = new QTimer(nullptr);
this->moveToThread(&t);
timer->moveToThread(&t);
QObject::connect(&t, &QThread::finished, this, &QObject::deleteLater);
t.start();
QObject::connect(timer, &QTimer::timeout, this, &Worker::dataTimerFunction);
QObject::connect(this, &Worker::stopTimer, timer, &QTimer::stop, Qt::QueuedConnection);
QObject::connect(this, &Worker::startTimer, timer, static_cast<void (QTimer::*)(int)>(&QTimer::start), Qt::QueuedConnection);
startTimer(200);
}
void Worker::dataTimerFunction()
{
qDebug()<<count;
count++;
if (count>5){
stopTimer();
}
}