当QStateMachine关闭时，我如何终止QDialog？

Question

我有QDialog和QStateMachine。当所有应用程序关闭时，此循环终止，但当Q对话框关闭时，我希望终止循环。我怎么能这么做？

  QStateMachine sm;
  QState s1(&sm), s2(&sm);
  sm.setInitialState(&s1);
  QEventTransition transition(dialog, QEvent::Close);
  s2.addTransition(&transition);
  QEventLoop loop;
  QObject::connect(&s2, &QState::entered, &loop, &QEventLoop::quit);
  sm.start();
  dialog->show();
  loop.exec();

Answer 1

为此使用QFinalState类。在文档示例中，显示了QPushButton和exit的用法。例如，您只需将其与finished()信号连接即可。

UPD

一些用法示例：

MainWinow.h

class MainWindow : public QMainWindow, private Ui::MainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);

private:
    QDialog *dialog;
private slots:
    void on_pushButton_clicked();
};

MainWindow.cpp

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    setupUi(this);

    dialog = new QDialog;
}

void MainWindow::on_pushButton_clicked()
{
    // Open dialog after push button was clicked
    if (!dialog)
        dialog = new QDialog;

    QEventLoop loop;
    QStateMachine machine;
    QState *s1 = new QState();

    QFinalState *s2 = new QFinalState();
    s1->addTransition(dialog, SIGNAL(finished(int)), s2);

    connect(&machine, QStateMachine::finished, [&loop]{
        qDebug() << "Finished";
        loop.quit();
    });

    machine.addState(s1);
    machine.addState(s2);
    machine.setInitialState(s1);
    machine.start();


    dialog->show();
    loop.exec();

    qDebug() << "Really finished";
}

因此，我们创建QEventLoop、QStateMachine和add状态(init状态和最终状态)。然后将QDialog::finished()信号连接到最终状态，并将QStateMachine::finished()信号与中断事件循环的时隙连接起来。然后显示QDialog并启动QStateMachine。

控制台将打印：

完成 真已完成