样条线图表范例

范例展示如何创建简单样条线图表。

运行范例

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

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.

QSplineSeries *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.

QChart *chart = new QChart();
chart->legend()->hide();
chart->addSeries(series);
chart->setTitle("Simple spline chart example");
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. We also set the Antialiasing on to have the rendered lines look nicer.

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

Finally, we set the QChartView as the windows's central widget.

QMainWindow window;
window.setCentralWidget(chartView);
window.resize(400, 300);
window.show();
					

范例工程 @ code.qt.io

内容

• 运行范例

• 创建样条线图表