What is the alternative to QTimer?

问题

The slot function QTimer::start have a interval of millisecond:

Starts or restarts the timer with a timeout interval of msec milliseconds.

But msec is a int type and couldn't take a long interval. What is a alternative to QTimer which could take a long interval ?

回答1:

In this case you can use something like an hourly timer connected to a function or lambda that checks the current timepoint against a target...

/*
 * We want to trigger some event one year from now.
 */
auto endpoint = QDateTime::now().addYears(1);
QTimer hourly_timer;
QObject::connect(&hourly_timer, &QTimer::timeout,
                 [endpoint]()
                   {
                     if (QDateTime::now() >= endpoint) {

                       /*
                        * Target time reached.  Do whatever...
                        */
                     }
                   });
hourly_timer.start(3600 * 1000);

来源：https://stackoverflow.com/questions/62481663/what-is-the-alternative-to-qtimer