用于设置取消时，询问是否保存修改的DLG
void SetWindow::cancelButton()

{

    if( m_IsChange)

    {

        QMessageBox msgBox;

        msgBox.setText(tr("The crap has been changed."));

        msgBox.setInformativeText(tr("Do you want to save your changes?"));

        msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);

        msgBox.setDefaultButton(QMessageBox::Save);

        int ret = msgBox.exec();

        switch (ret)

        {

            case QMessageBox::Discard:

                m_IsChange = false;

            case QMessageBox::Save:

                okButton();

                break;

            case QMessageBox::Cancel:

            default:

                break;

        }

    }

    else

    {

        okButton();

    }

}