AreaChart Example | Qt Charts 5.15.18

- Qt 5.15
- Qt Charts
- Qt Charts Examples
- AreaChart Example
- Qt Charts | Commercial or GPLv3

# AreaChart Example

The example shows how to create a simple area chart.

#### Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

#### Creating Area Charts

To create area charts, we need two QLineSeries instances. They are going to define the upper and lower boundary of the area.

         QLineSeries *series0 = new QLineSeries();
         QLineSeries *series1 = new QLineSeries();

We add data to both series and use the stream operator.

         *series0 << QPointF(1, 5) << QPointF(3, 7) << QPointF(7, 6) << QPointF(9, 7) << QPointF(12, 6)
                  << QPointF(16, 7) << QPointF(18, 5);
         *series1 << QPointF(1, 3) << QPointF(3, 4) << QPointF(7, 3) << QPointF(8, 2) << QPointF(12, 3)
                  << QPointF(16, 4) << QPointF(18, 3);

Now we create a QAreaSeries instance using two line series objects. We set the custom gradient fill and width of the outline.

         QAreaSeries *series = new QAreaSeries(series0, series1);
         series->setName("Batman");
         QPen pen(0x059605);
         pen.setWidth(3);
         series->setPen(pen);

         QLinearGradient gradient(QPointF(0, 0), QPointF(0, 1));
         gradient.setColorAt(0.0, 0x3cc63c);
         gradient.setColorAt(1.0, 0x26f626);
         gradient.setCoordinateMode(QGradient::ObjectBoundingMode);
         series->setBrush(gradient);

Last we create the QChartView instance, set the title, set anti-aliasing, and add the area series. We also create the default axes and specify the ranges on them.

         QChart *chart = new QChart();
         chart->addSeries(series);
         chart->setTitle("Simple areachart example");
         chart->createDefaultAxes();
         chart->axes(Qt::Horizontal).first()->setRange(0, 20);
         chart->axes(Qt::Vertical).first()->setRange(0, 10);

The chart is ready to be shown.

         QChartView *chartView = new QChartView(chart);
         chartView->setRenderHint(QPainter::Antialiasing);

Example project @ code.qt.io