按钮长按循环触发小例子

/* 启用循环触发按钮的功能。 */
setAutoRepeat(true); 
/* 设置长按1000ms后触发。*/
setAutoRepeatDelay(1000);

#include <QApplication>
#include <QPushButton>
#include <QDebug>

int main(int argc, char **argv)
{
    QApplication a(argc, argv);
    QPushButton *button = new QPushButton("Hello world");
    button->setAutoRepeat(true);
    button->setAutoRepeatDelay(1000);

    QObject::connect(button,
                     &QPushButton::clicked,
                     [](){
                         static int i = 0;
                         qDebug() << ">>>" << i++;
                     });
    button->show();
    return a.exec();
}