//自定义
QMessageBox box;
box.setWindowTitle(tr("警告"));
box.setIcon(QMessageBox::Warning);
box.setText(curFile+tr("尚未保存,是否保存？"));
box.setStandardButtons(QMessageBox::Yes|QMessageBox::No);
if(box.exec()==QMessageBox::Yes)    do_file_Save();
QMessageBox::critical(NULL,"critical","Content", 
	QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
//第二种
QMessageBox message(QMessageBox::NoIcon,"Show Qt","Do you want to show Qt dialog?", QMessageBox::Yes | QMessageBox::No, NULL);
if(message.exec() == QMessageBox::Yes)
{
QMessageBox::aboutQt(NULL,"About Qt");
}
//第三中
QMessageBox::StandardButton rb = QMessageBox::question(NULL,"Show Qt","Do you want to show Qt dialog?", QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
if(rb == QMessageBox::Yes)
{
QMessageBox::aboutQt(NULL,"About Qt");
}