Question

我正在尝试创建一个单击按钮后显示图表的应用程序。

我正在MainWindow类中创建图表。

图表.h

class Chart: public QChart
{
    Q_OBJECT
public:
    Chart(QGraphicsItem *parent = 0, Qt::WindowFlags wFlags = 0);
    QTimer m_timer;
    virtual ~Chart();
public slots:
    void handleTimeout();
private:    
    QSplineSeries *m_series;
    QStringList m_titles;
    QValueAxis *m_axis;
    qreal m_step;
    qreal m_x;
    qreal m_y;
};

chart.cpp

Chart::Chart(QGraphicsItem *parent, Qt::WindowFlags wFlags) :
    QChart(QChart::ChartTypeCartesian, parent, wFlags),
    m_series(0),
    m_axis(new QValueAxis),
    m_step(0),
    m_x(5),
    m_y(1)
{
    qsrand((uint)QTime::currentTime().msec());
    QObject::connect(&m_timer, &QTimer::timeout, this, &Chart::handleTimeout);
    m_timer.setInterval(1000);
    m_series = new QSplineSeries(this);
    QPen green(Qt::red);
    green.setWidth(3);
    m_series->setPen(green);
    m_series->append(m_x, m_y);

    addSeries(m_series);
    createDefaultAxes();
    setAxisX(m_axis, m_series);
    m_axis->setTickCount(5);
    axisX()->setRange(0, 10);
    axisY()->setRange(-5, 10);
    qDebug() << "created";
    m_timer.start();
}

Chart::~Chart()
{
    qDebug() << "Destroyed";
}

void Chart::handleTimeout()
{
    qreal x = plotArea().width() / m_axis->tickCount();
    qreal y = (m_axis->max() - m_axis->min()) / m_axis->tickCount();
    m_x += y;
    m_y = qrand() % 5 - 2.5;
    m_series->append(m_x, m_y);
    scroll(x, 0);
    qDebug() << "Date:";
    if (m_x == 100)
        m_timer.stop();
}

mainclass.h

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow();
    Chart *chart;
protected:
public slots: void slot1();
private:
        QDialogButtonBox *buttonBox;

};

mainclass.cpp

MainWindow::MainWindow()
{
    buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);

    connect(buttonBox, SIGNAL(accepted()), this, SLOT(slot1()));
    connect(buttonBox, SIGNAL(rejected()), this, SLOT(slot2()));

    QDockWidget *dock = new QDockWidget(tr("dialog"), this);

    dock->setWidget(buttonBox);
    addDockWidget(Qt::TopDockWidgetArea, dock);
}
void MainWindow::slot1()
{
        Chart *chart = new Chart;
    chart->setTitle("Dynamic spline chart");
    chart->legend()->hide();
    chart->setAnimationOptions(QChart::AllAnimations);
    QChartView chartView(chart);
    chartView.setRenderHint(QPainter::Antialiasing);

    QWidget *window = new QWidget;

    formGroupBox = new QGroupBox(tr("Form layout"));
    QFormLayout *layout = new QFormLayout;
    layout->addWidget(&chartView);
        window->setLayout(layout);
    window->show();
}

main.cpp

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow mainWin;
    mainWin.show();
    return app.exec();
}

在MainWindow类中正在创建图表对象，但该对象立即被销毁。我认为继承存在一些问题。我不太擅长QT的继承如果问题解决了，那将真的很有帮助。

从MainWindow类调用时，QT QChart被破坏

0 个答案: