前言
红胖子，来也！
按照顺序，本章为样条曲线图。
补充
QCharts所有的图表都依赖《Qt开发技术：QCharts（一）QCharts基本介绍以及图表框架详解》中的QChart、QChartView、QLegend、QValueAxis。
Demo
Demo下载地址
CSDN：https://download.csdn.net/download/qq21497936/12685603
QQ群：1047134658（点击“文件”搜索“qChartsTools”，群内与博文同步更新）
样条曲线图
概述
折线图和样条曲线图将数据表示为一系列由直线连接的数据点。在折线图中，数据点由直线连接，而在样条曲线图中，数据点由样条曲线连接。样条曲线是使用QPainterPath绘制的。
样条曲线图是通过使用继承QLineSeries的QSplineSeries类或继承LineSeries的SplineSeries类型实现的。
QSplineSeries（样条曲线图）
概述
QSplineSeries类将数据显示为样条曲线图。
样条曲线系列存储QPainterPath绘制样条曲线所需的数据点和段控制点。当数据发生变化时，自动计算控制点。该算法计算点以便绘制法向样条曲线。
创建样条曲线图：
// 方式一：逐一添加，大批量数据较慢 QSplineSeries* pSeries = new QSplineSeries(); pSeries->append(0, 6); pSeries->append(2, 4); ... chart->addSeries(pSeries);
效率更高的方式为：
// 方式二：逐一添加，大批量数据插入 _pSplineSeries = new QSplineSeries; _pSplineSeries2 = new QSplineSeries; _pSplineSeries3 = new QSplineSeries; _pSplineSeries4 = new QSplineSeries; QList<QSplineSeries *> listLine; listLine.append(_pSplineSeries); listLine.append(_pSplineSeries2); listLine.append(_pSplineSeries3); listLine.append(_pSplineSeries4); for(int index = 1; index < 4; index++) { QList<QPointF> listPointF; for(int index = 0; index < 11; index++) { listPointF << QPointF(index, qrand()%11); } listLine.at(index)->append(listPointF); listLine.at(index)->setName(QString("通道%1").arg(index+1)); listLine.at(index)->setPen(QPen(QColor(qrand()%256, qrand()%256, qrand()%256), 2)); // 通用：将数据插入到图表中 _pChart->addSeries(listLine.at(index)); }
注意：样条曲线图的QSplineSeries类的使用请参考QXYSeries的使用。
QSplineSeries类以样条曲线图的形式显示数据。
QXYSeries（折线图、样条曲线图、散点图的基类）
概述
QXYSeries类是折线图、样条曲线图、散点图的基类，QSplineSeries、QLineSeries、QScatterSeries都参照该类使用。
属性
Demo核心代码解析
建立QChart的显示框架
SplineChartWidget::SplineChartWidget(QWidget *parent) : QWidget(parent), _pChartView(0), _pChart(0), _pXValueAxis(0), _pYValueAxis(0), _pLegend(0), _pLineSeries(0), _pLineSeries2(0), _pLineSeries3(0), _pLineSeries4(0) { _pChartView = new QChartView(this); _pChart = new QChart(); initData(); } void SplineChartWidget::resizeEvent(QResizeEvent *event) { if(_pChartView) { _pChartView->setGeometry(rect()); } }
(本文章博客地址：https://blog.csdn.net/qq21497936/article/details/108022984)
初始化数据
void SplineChartWidget::initData() { _pSplineSeries = new QSplineSeries; _pSplineSeries2 = new QSplineSeries; _pSplineSeries3 = new QSplineSeries; _pSplineSeries4 = new QSplineSeries; // 方式一：逐一添加，大批量数据较慢 _pSplineSeries->append(0, qrand()%11); _pSplineSeries->append(1, qrand()%11); _pSplineSeries->append(2, qrand()%11); _pSplineSeries->append(3, qrand()%11); _pSplineSeries->append(4, qrand()%11); _pSplineSeries->append(5, qrand()%11); _pSplineSeries->append(6, qrand()%11); _pSplineSeries->append(7, qrand()%11); _pSplineSeries->append(8, qrand()%11); _pSplineSeries->append(9, qrand()%11); _pSplineSeries->append(10, qrand()%11); _pSplineSeries->setName("通道1"); _pSplineSeries->setPen(QPen(QColor(qrand()%256, qrand()%256, qrand()%256), 2)); // 通用：将数据插入到图表中 _pChart->addSeries(_pSplineSeries); // 方式二：逐一添加，大批量数据较慢 QList<QSplineSeries *> listLine; listLine.append(_pSplineSeries); listLine.append(_pSplineSeries2); listLine.append(_pSplineSeries3); listLine.append(_pSplineSeries4); for(int index = 1; index < 4; index++) { QList<QPointF> listPointF; for(int index = 0; index < 11; index++) { listPointF << QPointF(index, qrand()%11); } listLine.at(index)->append(listPointF); listLine.at(index)->setName(QString("通道%1").arg(index+1)); listLine.at(index)->setPen(QPen(QColor(qrand()%256, qrand()%256, qrand()%256), 2)); // 通用：将数据插入到图表中 _pChart->addSeries(listLine.at(index)); } // 通用：X轴和Y轴的处理(先插入数据再处理轴,否则不会有轴) _pChart->createDefaultAxes(); _pYValueAxis = dynamic_cast<QValueAxis *>(_pChart->axisY()); // _pYValueAxis = new QValueAxis(_pChart); _pYValueAxis->setRange(0, 10); _pYValueAxis->setLinePen(QPen(Qt::black, 1)); // tick _pYValueAxis->setTickCount(5); _pYValueAxis->setGridLinePen(QPen(Qt::gray, 1)); _pYValueAxis->setGridLineVisible(true); // subTick _pYValueAxis->setMinorTickCount(4); _pYValueAxis->setMinorGridLineVisible(true); _pYValueAxis->setLabelFormat("%d"); // _pChart->addAxis(_pYValueAxis, Qt::AlignLeft); _pXValueAxis = dynamic_cast<QValueAxis *>(_pChart->axisX()); // _pXValueAxis = new QValueAxis(_pChart); _pXValueAxis->setRange(0, 10); _pXValueAxis->setLinePen(QPen(Qt::black, 1)); // tick _pXValueAxis->setTickCount(5); _pXValueAxis->setGridLinePen(QPen(Qt::gray, 1)); _pXValueAxis->setGridLineVisible(true); // subTick _pXValueAxis->setMinorTickCount(4); // 相反 _pXValueAxis->setMinorGridLineVisible(true); _pXValueAxis->setLabelFormat("%d s"); // _pChart->addAxis(_pXValueAxis, Qt::AlignBottom); // 通用：视图显示设置为图表 _pChartView->setRubberBand(QChartView::NoRubberBand); // 不缩放 _pChartView->setDragMode(QChartView::NoDrag); // 拽拖：需要自己重写QCharView _pChartView->setChart(_pChart); // 标识 _pLegend = _pChart->legend(); _pLegend->setAlignment(Qt::AlignRight); // 平滑 _pChartView->setRenderHint(QPainter::Antialiasing, true); // 阴影 _pChart->setDropShadowEnabled(true); }
设置数据线是否显示（标签显示会同步）
void SplineChartWidget::setDataVisible(int index, bool visible) { if(index < 0 || index > 3) { return; } QList<QSplineSeries *> listLine; listLine.append(_pSplineSeries); listLine.append(_pSplineSeries2); listLine.append(_pSplineSeries3); listLine.append(_pSplineSeries4); listLine.at(index)->setVisible(visible); }
设置主题样式
void SplineChartWidget::setTheme(QChart::ChartTheme theme) { _pChart->setTheme(theme); }
设置动画模式
void SplineChartWidget::setAnimationOptions(QChart::AnimationOption option) { _pChart->setAnimationOptions(option); }
设置标签显示位置
void SplineChartWidget::setAlignment(Qt::Alignment align) { _pLegend->setAlignment(align); }
设置标签是否可见
void SplineChartWidget::setLegendVisible(bool visible) { _pLegend->setVisible(visible); _pChartView->setRenderHint(QPainter::Antialiasing); }
设置是否绘制平滑
void SplineChartWidget::setAntialiasing(bool antialiasing) { _pChartView->setRenderHint(QPainter::Antialiasing, antialiasing); }
设置是否有阴影
void SplineChartWidget::setShadow(bool shadow) { _pChart->setDropShadowEnabled(shadow); }
重置随机数据
void SplineChartWidget::resetData() { _pChart->removeAllSeries(); _pSplineSeries = new QSplineSeries; _pSplineSeries2 = new QSplineSeries; _pSplineSeries3 = new QSplineSeries; _pSplineSeries4 = new QSplineSeries; QList<QSplineSeries *> listLine; listLine.append(_pSplineSeries); listLine.append(_pSplineSeries2); listLine.append(_pSplineSeries3); listLine.append(_pSplineSeries4); for(int index = 0; index < 4; index++) { QList<QPointF> listPointF; for(int index = 0; index < 11; index++) { listPointF << QPointF(index, qrand()%11); } listLine.at(index)->append(listPointF); listLine.at(index)->setName(QString("通道%1").arg(index+1)); listLine.at(index)->setPen(QPen(QColor(qrand()%256, qrand()%256, qrand()%256), 2)); _pChart->addSeries(listLine.at(index)); } resetColor(); }
重置随机颜色
void SplineChartWidget::resetColor() { QList<QLineSeries *> listLine; listLine.append(_pSplineSeries); listLine.append(_pSplineSeries2); listLine.append(_pSplineSeries3); listLine.append(_pSplineSeries4); for(int index = 0; index < listLine.size(); index++) { listLine.at(index)->setColor(QColor(qrand()%256, qrand()%256, qrand()%256)); } }
工程模板：对应版本号v1.0.0
对应版本号v1.0.0
