/** 
 * int output = QMessageBox::icon(this, tr("Title"), tr("content"),
 *                              QMessageBox::button, QMessageBox::defaultButton);
 */
//for example :
int ret = QMessageBox::warning(this, tr("My Application"),
                               tr("The document has been modified.\n"
                                  "Do you want to save your changes?"),
                               QMessageBox::Save | QMessageBox::Discard
                               | QMessageBox::Cancel,
                               QMessageBox::Save);