void MainWindow::slot_set()
{
menu->exec(QPoint(QCursor::pos().x(), QCursor::pos().y() + 15));
}
about_action = new QAction("\345\205\263\344\272\216", this);
auto set_action = new QAction("\350\256\276\347\275\256", this);
connect(about_action, SIGNAL(triggered()), this, SLOT(slot_about_()));
connect(set_action, SIGNAL(triggered()), this, SLOT(slot_set_()));
menu = new QMenu(this);
menu->addAction(set_action);
menu->addAction(about_action);
connect(ui->pushButton_6, SIGNAL(clicked()), this, SLOT(slot_set()));