区域图表范例

展示如何创建简单区域图表的范例。

运行范例

要运行范例从 Qt Creator ,打开 欢迎 模式,然后选择范例从 范例 。更多信息,拜访 构建和运行范例 .

创建区域图表

要创建区域图表 需要 2 个 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);
					

图表展示就绪。

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

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