用任意一个按键模拟TAB按键的功能

void tab_simulate()
{
    QKeyEvent event(QEvent::KeyPress, Qt::Key_Tab, Qt::NoModifier);
    QApplication::sendEvent(this, &event);

    QWidget* widget = this->focusWidget();
    QPushButton* pushbutton = dynamic_cast<QPushButton*>(widget);
    while (pushbutton == 0)
    {
        QKeyEvent event(QEvent::KeyPress, Qt::Key_Tab, Qt::NoModifier);
        QApplication::sendEvent(this, &event);
        widget = this->focusWidget();
        pushbutton = dynamic_cast<QPushButton*>(widget);
    }
}

把它作为一个槽函数，用一个按钮的click()信号来和它connect起来即可