#include <QApplication>
#include <QChartView>
#include <QLineSeries>

#include <QDebug>

QVector<QPointF> convertLine2Step(const QVector<QPointF> &points)
{
? ? QVector<QPointF> s;
? ? s << points.at(0);
? ? int x, y;
? ? for (int i = 1; i < points.count(); i++)
? ? {
? ? ? ? x = points.at(i).x();
? ? ? ? y = points.at(i - 1).y();
? ? ? ? s << QPointF(x, y);
? ? ? ? s << points.at(i);
? ? }
? ? return s;
}

int main(int argc, char *argv[])
{
? ? QApplication a(argc, argv);
? ? QtCharts::QChartView w;
? ? w.setRenderHint(QPainter::Antialiasing);
? ? QtCharts::QChart chart;
? ? chart.legend()->setVisible(true);
? ? w.setChart(&chart);
? ? QtCharts::QLineSeries *series = new QtCharts::QLineSeries;
? ? QVector<QPointF> points;
? ? points << QPointF(2, 4);
? ? points << QPointF(3, 8);
? ? points << QPointF(7, 4);
? ? points << QPointF(10, 5);
? ? points << QPointF(11, 1) << QPointF(13, 3) << QPointF(17, 6) << QPointF(18, 3)
? ? ? ? ? ?<< QPointF(20, 2);

? ? *series << points.toList();
? ? series->setName("original");

? ? QtCharts::QLineSeries *stepSerie = new QtCharts::QLineSeries;
? ? *stepSerie << convertLine2Step(points).toList();
? ? stepSerie->setName("step");
? ? chart.addSeries(series);
? ? chart.addSeries(stepSerie);
? ? chart.createDefaultAxes();
? ? chart.setTitle("Simple line chart example");
? ? w.show();
? ? return a.exec();
}