How to use ChartView at DockWidget

yanagida

I tried adding ChartView to DockWidget but ChartView was not shown(only blank dockwidget was shown).
The code is as follows.

[mainwindow.cpp]
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    Chart *chart = new Chart;
    chart->setTitle("Chart");
    chart->legend()->hide();
    chart->setAnimationOptions(QChart::AllAnimations);

    QChartView chartView(chart);
    chartView.setRenderHint(QPainter::Antialiasing);

    QDockWidget *chartwidget = new QDockWidget();
    chartwidget->setWidget(&chartView);
    addDockWidget(Qt::LeftDockWidgetArea, chartwidget);

    ui->setupUi(this);
}

However, following code could show the chartview at dockwidget.

[main.cpp]
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;

    Chart *chart = new Chart;
    chart->setTitle("Chart");
    chart->legend()->hide();
    chart->setAnimationOptions(QChart::AllAnimations);

    QChartView chartView(chart);
    chartView.setRenderHint(QPainter::Antialiasing);

    QDockWidget *chartwidget = new QDockWidget();
    chartwidget->setWidget(&chartView);
    w.addDockWidget(Qt::LeftDockWidgetArea, chartwidget);

    w.show();

    return a.exec();
}

Why is chartview not shown in the mainwindow.cpp?

Thanks

mrjj

Hi and welcome
You might have classic error where the object runs out of scope.

QChartView chartView(chart); << not using new. so local variable
chartwidget->setWidget(&chartView); << assign to other object
} << here chartView is deleted. runs out of scope. when function ends.

It did work in the "working" sample as return a.exec() prevented it from running out of scope
as it stays in there until app ends.

yanagida

@mrjj

Thank you for your reply!!
I did solve the problem.