1  void MainWindow::on_pushButton_2_clicked()
2  {
3    QMessageBox msgBox;
4    msgBox.setText("The document has been modified.");
5    msgBox.setInformativeText("Do you want to save your changes?");
6    msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
7    msgBox.setDefaultButton(QMessageBox::Save);
8    msgBox.setDetailedText("You have to notice carefully!");
9    msgBox.setWindowTitle("Button message");
10   switch (msgBox.exec()) {
11     case QMessageBox::Save:
12         QMessageBox::information(this, "Simple box", "You clicked Save");
13         break;
14     case QMessageBox::Discard:
15         QMessageBox::information(this, "Simple box", "You clicked Discard");
16         break;
17     case QMessageBox::Cancel:
18         QMessageBox::information(this, "Simple box", "You clicked Cancel");
19         break;
20     default:
21         // should never be reached
22         break;
23   }
24 }