Qt-绘制图表

1  简介

使用Qt的charts模块来绘制图表，案例来自Qt自带的demo。

charts模块简介：Qt Chars模块提供了一系列容易使用的图表组件。需要使用charts组件时，需要导入Qt Charts模块，通过如下方式：QT += charts

在安装Qt Creator的时候，需要勾选上这个模块，不然是不能使用的。

2  Qt Charts总览

Qt Chars支持绘制：坐标图、柱状图、折线图、饼图、曲线图、散点图等。

3  测试及说明

首先创建一个工程，继承至MainWindow组件。

（1）绘制折线图

折线图通过线段展示一系列相关联的点。

使用的类：QLineSeries

测试代码：

 MainWindow::MainWindow(QWidget *parent) :
     QMainWindow(parent),
     ui(new Ui::MainWindow)
 {
     ui->setupUi(this);

     /*
      * LineChart Example
      */
     //添加一个QLineSeries实例
     QLineSeries *lineseries = new QLineSeries();
     //添加数据（点），有两种方式
     lineseries->append(, );  //参数分别为横纵坐标
     lineseries->append(, );
     lineseries->append(, );
     lineseries->append(, );
     *lineseries << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, );
     //添加一个QChart实例，为了展示数据
     QChart *chart = new QChart();
     chart->legend()->hide();  //隐藏图例
     chart->addSeries(lineseries);
     chart->createDefaultAxes();
     chart->setTitle("Simple line chart example");
     //添加一个QChartView图例
     QChartView *chartView = new QChartView(chart);
     chartView->setRenderHint(QPainter::Antialiasing);  //呈现方式
     //显示
     this->setCentralWidget(chartView);
     this->setCentralWidget(chartView);
     this->resize(, );
     this->show();
 }

运行测试：

（2）绘制曲线图

使用的类：QSplineSeries

测试代码：

     QSplineSeries *series = new QSplineSeries();
     series->setName("spline");
     series->append(, );
     series->append(, );
     series->append(, );
     series->append(, );
     series->append(, );

     QChart *chart = new QChart();
     chart->legend()->hide();
     chart->addSeries(series);
     chart->setTitle("Simple spline chart example");
     chart->createDefaultAxes();
     chart->axisY()->setRange(, );

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

     this->setCentralWidget(chartView);
     this->setCentralWidget(chartView);
     this->resize(, );
     this->show();

运行测试：

（3）绘制面积图

使用的类：LineChart

测试代码：

     QLineSeries *series0 = new QLineSeries();
     QLineSeries *series1 = new QLineSeries();
     *series0 << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, )
              << QPointF(, ) << QPointF(, );
     *series1 << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, )
              << QPointF(, ) << QPointF(, );

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

     QChart *chart = new QChart();
     chart->addSeries(series);
     chart->setTitle("Simple areachart example");
     chart->createDefaultAxes();
     chart->axisX()->setRange(, );
     chart->axisY()->setRange(, );

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

     this->setCentralWidget(chartView);
     this->setCentralWidget(chartView);
     this->resize(, );
     this->show();

运行测试：

（4）绘制散点图

使用的类： QScatterSeries

测试代码：

     QScatterSeries *series0 = new QScatterSeries();
     series0->setName("scatter1");
     series0->setMarkerShape(QScatterSeries::MarkerShapeCircle);
     series0->setMarkerSize(5.0);

     QScatterSeries *series1 = new QScatterSeries();
     series1->setName("scatter2");
     series1->setMarkerShape(QScatterSeries::MarkerShapeRectangle);
     series1->setMarkerSize(10.0);

     QScatterSeries *series2 = new QScatterSeries();
     series2->setName("scatter3");
     series2->setMarkerShape(QScatterSeries::MarkerShapeRectangle);
     series2->setMarkerSize(15.0);

     series0->append(, );
     series0->append(, );
     series0->append(, );
     series0->append(, );
     series0->append(, );
     *series1 << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, );
     *series2 << QPointF(, ) << QPointF(, ) << QPointF(, ) << QPointF(, );

     QChart *chart = new QChart();
     chart->addSeries(series0);
     chart->addSeries(series1);
     chart->addSeries(series2);
     chart->setTitle("Simple scatterchart example");
     chart->createDefaultAxes();
     chart->setDropShadowEnabled(false);

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

     this->setCentralWidget(chartView);
     this->resize(, );
     this->show();

运行测试：

（5）绘制柱状图

使用的类：

测试代码：

     QBarSet *set0 = new QBarSet("Jane");
     QBarSet *set1 = new QBarSet("John");
     QBarSet *set2 = new QBarSet("Axel");
     QBarSet *set3 = new QBarSet("Mary");
     QBarSet *set4 = new QBarSet("Samantha");

     *set0 <<  <<  <<  <<  <<  << ;
     *set1 <<  <<  <<  <<  <<  << ;
     *set2 <<  <<  <<  <<  <<  << ;
     *set3 <<  <<  <<  <<  <<  << ;
     *set4 <<  <<  <<  <<  <<  << ;

     QBarSeries *series = new QBarSeries();
     series->append(set0);
     series->append(set1);
     series->append(set2);
     series->append(set3);
     series->append(set4);

     QChart *chart = new QChart();
     chart->addSeries(series);
     chart->setTitle("Simple barchart example");
     chart->setAnimationOptions(QChart::SeriesAnimations);

     QStringList categories;
     categories << "Jan" << "Feb" << "Mar" << "Apr" << "May" << "Jun";
     QBarCategoryAxis *axis = new QBarCategoryAxis();
     axis->append(categories);
     chart->createDefaultAxes();
     chart->setAxisX(axis, series);

     chart->legend()->setVisible(true);
     chart->legend()->setAlignment(Qt::AlignBottom);

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

     this->setCentralWidget(chartView);
     this->resize(, );
     this->show();

运行测试：

 （6）绘制饼图

使用的类：QPieSeries

测试代码：

     QPieSeries *series = new QPieSeries();
     series->append("Jane", );
     series->append("Joe", );
     series->append("Andy", );
     series->append("Barbara", );
     series->append("Axel", );

     QPieSlice *slice = series->slices().at();
     slice->setExploded();
     slice->setLabelVisible();
     slice->setPen(QPen(Qt::darkGreen, ));
     slice->setBrush(Qt::green);

     QChart *chart = new QChart();
     chart->addSeries(series);
     chart->setTitle("Simple piechart example");
     chart->legend()->hide();

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

     this->setCentralWidget(chartView);
     this->resize(, );
     this->show();

运行测试：