Qt 代码： QMessageBox 用法

案例一:

QMessageBox msgBox;
msgBox.setText("The document has been modified.");
msgBox.setInformativeText("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::Save:
 // Save was clicked
 break;
 case QMessageBox::Discard:
 // Don't Save was clicked
 break;
 case QMessageBox::Cancel:
 // Cancel was clicked
 break;
 default:
 // should never be reached
 break;
 }

      案例二：

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);

案例三：添加按钮、判断哪个按钮按下

QMessageBox msgBox;
QPushButton *connectButton = msgBox.addButton(tr("Connect"), QMessageBox::ActionRole);
QPushButton *abortButton = msgBox.addButton(QMessageBox::Abort);
if(msgBox.clickedButton() == connectButton)
{
     // connect
}
else if(msgBox.clickedButton() == abortButton)
{
     // abort
}
msgBox.exec();