RibbonGroup添加 QCheckBox：

 QCheckBox* pCheck = new QCheckBox(tr("Check"));
  pCheck->setToolTip(tr("Check"));
 groupClipboard->addWidget(pCheck);
 connect(pCheck, SIGNAL(stateChanged(int)), this, SLOT(checkClick(int)));

点击事件：

protected slots:
    void checkClick(int state);

void QRibbonDemo::checkClick(int state)
{
    QMessageBox messageBox(QMessageBox::Information, windowTitle(),
        QLatin1String(""), QMessageBox::Ok, this);
    messageBox.setInformativeText(QLatin1String("check click."));
    messageBox.exec();
}