#include "mainwindow.h" #include "ui_mainwindow.h" #include #include #include QT_CHARTS_USE_NAMESPACE MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); const int count = 1495; //if set series->setUseOpenGL(true); //const double _xmin(17249.999500); //don't show chart //const double _xmax(17250.000500); //don't show chart const double _xmin(17249.999500); //stairs const double _xmax(17250.015500); //stairs //const double _xmin(17000.999500); //work very well //const double _xmax(17500.000500); //work very well const double _ymin(4.0); const double _ymax(8.0); double _xstep((_xmax-_xmin)/count); double _ystep((_ymax-_ymin)/count); QValueAxis* _axisX = new QValueAxis; QValueAxis* _axisY = new QValueAxis; _axisX->setRange(_xmin, _xmax); _axisY->setRange(_ymin, _ymax); //![1] QLineSeries *series = new QLineSeries(); //![1] connect(series, SIGNAL(useOpenGlChanged()), this, SLOT(doUseOpenGlChanged())); for(int i=0; iappend(_xmin + _xstep*i, _ymin + _ystep*i); } series->setUseOpenGL(true); bool useOpenGL = series->useOpenGL(); //![2] //series->append(0, 6); //series->append(2, 4); //series->append(3, 8); //series->append(7, 4); //series->append(10, 5); //*series << QPointF(11, 1) << QPointF(13, 3) << QPointF(17, 6) << QPointF(18, 3) << QPointF(20, 2); //![2] //![3] QChart *chart = new QChart(); chart->legend()->hide(); chart->addSeries(series); chart->createDefaultAxes(); chart->setTitle("Simple line chart example"); //![3] chart->setAxisX(_axisX, series); chart->setAxisY(_axisY, series); //![4] QChartView *chartView = new QChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); //![4] this->setCentralWidget(chartView); this->resize(600, 400); //this->show(); } MainWindow::~MainWindow() { delete ui; } void MainWindow::doUseOpenGlChanged(void) { QMessageBox msgBox; msgBox.setText("signal useOpenGlChanged"); msgBox.exec(); } //I can see on help - https://doc.qt.io/qt-5/qabstractseries.html#useOpenGL-prop //Signals... //void useOpenGLChanged() //but when I run the application I've got the message //QObject::connect: No such signal QtCharts::QLineSeries::useOpenGlChanged()