QTime to QTimer

Question

How can I transform QTime to QTimer so I could print the left time to qDebug? Here's some code:

QTime time = QTime::fromString("23:54", "hh:mm");

How can I take one second away from time every second and print the left time to qDebug?

Answer 1

You just have to use a QTimer that triggers every second, then you must decrease the time with addSecs(-1) and print it in an appropriate format:

#include <QCoreApplication>
#include <QTimer>
#include <QTime>
#include <QDebug>
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QTimer timer;

    QTime time = QTime::fromString("23:54", "hh:mm");

    QObject::connect(&timer, &QTimer::timeout, [&time](){
        time = time.addSecs(-1);
        qDebug()<<time.toString("hh:mm:ss");
    });
    timer.start(1000);

    return a.exec();
}