创建样条线图表

要创建样条线图表，需要将数据放入 QSplineSeries . QSplineSeries automatically calculates spline segment control points that are needed to properly draw the spline.

auto series = new QSplineSeries;
series->setName("Spline");
					

Now let's add some data points to the series.

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);
					

The data series has been populated. To display it on a chart we create a QChart object and add the data series to it. We also set the title and the values range on the y-axis, so that our chart's visibility is better.

auto chart = new QChart;
chart->legend()->hide();
chart->addSeries(series);
chart->setTitle("Simple Spline Chart");
chart->createDefaultAxes();
chart->axes(Qt::Vertical).first()->setRange(0, 10);
					

Then we create a QChartView 对象采用 QChart as a parameter. This way we don't need to create a QGraphicsView scene ourselves.

createDefaultChartView(chart);