Display Constantly Updated Time in Qt 6

In graphical user interface (GUI) applications, displaying real-time information is a common requirement. One fundamental element is the display of constantly updated time. Whether it's a digital clock in the application or a timestamp reflecting the current time, Qt provides a straightforward and efficient way to achieve this. This tutorial explains how to display constantly updated time in Qt 6.

In the main function, a QLabel is created and configured to show the time. The displayTime function is initially called to set the initial time. A QTimer is set up to trigger the displayTime function every second, ensuring the clock updates continuously. The current time is displayed in the hh:mm:ss format (e.g. 14:50:30).

#include <QApplication>
#include <QLabel>
#include <QTimer>
#include <QTime>

void displayTime(QLabel *label)
{
    label->setText(QTime::currentTime().toString("hh:mm:ss"));
}

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

    auto *label = new QLabel();
    label->setAlignment(Qt::AlignCenter);
    label->resize(200, 100);

    displayTime(label);
    label->show();

    QTimer timer;
    QObject::connect(&timer, &QTimer::timeout, [&label]() { displayTime(label); });
    timer.start(1000);

    return QApplication::exec();
}

Here's how the application looks: