主程序

#include <QCoreApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    MainWindow w;
    return a.exec();
}

mainwindow.cpp程序

#include "mainwindow.h"

#include <QDateTime>

MainWindow::MainWindow(QObject *parent)
    :QObject(parent)
{
    pTimer = new QTimer(this);
    pTimer->setInterval(10000);
    connect(pTimer, &QTimer::timeout, this, &MainWindow::slot10000msTimeOut);
    pTimer->start();
    qDebug() << "Start constructing MainWindow at:" << QDateTime::currentDateTime();

    if (pTimer->isActive()) {
        qDebug() << "Timer started successfully.";
    } else {
        qDebug() << "Timer failed to start.";
    }
}
MainWindow::~MainWindow()
{
    if(pTimer->isActive()){
        pTimer->stop();
    }
}

void MainWindow::slot10000msTimeOut()
{
    qDebug() << "End constructing MainWindow at:" << QDateTime::currentDateTime();
}

mainwindow.h头文件

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>
#include <QDebug>
class MainWindow : public QObject
{
    Q_OBJECT

public:
    MainWindow(QObject *parent = nullptr);
    ~MainWindow();

private:
    QTimer *pTimer;



private slots:
    void slot10000msTimeOut();
};
#endif // MAINWINDOW_H

总结了注意点：

关闭定时器，在程序结束的时候，再stop

声明了槽函数，是必须要去定义的。否则报错

QCoreApplication不依赖于任何 GUI 相关的库和功能