Qt中提供了强大的2D绘图系统,可以使用同一API实现在屏幕和绘图设备上进行绘制，本文就详细的介绍了Qt绘制坐标图、柱状图、折线图、饼图、曲线图、散点图等，感兴趣的可以了解一下
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(0, 6); //参数分别为横纵坐标 lineseries->append(2, 4); lineseries->append(3, 8); lineseries->append(7, 4); *lineseries << QPointF(11, 1) << QPointF(13, 3) << QPointF(17, 6) << QPointF(18, 3) << QPointF(20, 2); //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(400, 300); 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(0, 6); series->append(2, 4); series->append(3, 8); series->append(7, 4); series->append(10, 5); QChart *chart = new QChart(); chart->legend()->hide(); chart->addSeries(series); chart->setTitle("Simple spline chart example"); chart->createDefaultAxes(); chart->axisY()->setRange(0, 10); QChartView *chartView = new QChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); this->setCentralWidget(chartView); this->setCentralWidget(chartView); this->resize(400, 300); this->show();运行测试：
（3）绘制面积图
使用的类：QAreaSeries
测试代码：
QLineSeries *series0 = new QLineSeries(); QLineSeries *series1 = new QLineSeries(); *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); QAreaSeries *series = new QAreaSeries(series0, series1); series->setName("Batman"); QPen pen(0x059605); pen.setWidth(3); series->setPen(pen); QChart *chart = new QChart(); chart->addSeries(series); chart->setTitle("Simple areachart example"); chart->createDefaultAxes(); chart->axisX()->setRange(0, 20); chart->axisY()->setRange(0, 10); QChartView *chartView = new QChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); this->setCentralWidget(chartView); this->setCentralWidget(chartView); this->resize(400, 300); 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(0, 6); series0->append(2, 4); series0->append(3, 8); series0->append(7, 4); series0->append(10, 5); *series1 << QPointF(1, 1) << QPointF(3, 3) << QPointF(7, 6) << QPointF(8, 3) << QPointF(10, 2); *series2 << QPointF(1, 5) << QPointF(4, 6) << QPointF(6, 3) << QPointF(9, 5); 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(400, 300); this->show();运行测试：
（5）绘制柱状图
使用的类：QBarSeries
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 << 1 << 2 << 3 << 4 << 5 << 6; *set1 << 5 << 0 << 0 << 4 << 0 << 7; *set2 << 3 << 5 << 8 << 13 << 8 << 5; *set3 << 5 << 6 << 7 << 3 << 4 << 5; *set4 << 9 << 7 << 5 << 3 << 1 << 2; 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(400, 300); 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", 1); series->append("Joe", 2); series->append("Andy", 3); series->append("Barbara", 4); series->append("Axel", 5); QPieSlice *slice = series->slices().at(1); slice->setExploded(); slice->setLabelVisible(); slice->setPen(QPen(Qt::darkGreen, 2)); 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(400, 300); this->show();运行测试：
完整的测试代码：
#include "mainwindow.h" #include "ui_mainwindow.h" #include#include #include #include #include MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); #if 0 /* * 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(0, 6); //参数分别为横纵坐标 lineseries->append(2, 4); lineseries->append(3, 8); lineseries->append(7, 4); *lineseries << QPointF(11, 1) << QPointF(13, 3) << QPointF(17, 6) << QPointF(18, 3) << QPointF(20, 2); //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(400, 300); this->show(); #endif #if 0 /* * SplineChart Example */ QSplineSeries *series = new QSplineSeries(); series->setName("spline"); series->append(0, 6); series->append(2, 4); series->append(3, 8); series->append(7, 4); series->append(10, 5); QChart *chart = new QChart(); chart->legend()->hide(); chart->addSeries(series); chart->setTitle("Simple spline chart example"); chart->createDefaultAxes(); chart->axisY()->setRange(0, 10); QChartView *chartView = new QChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); this->setCentralWidget(chartView); this->setCentralWidget(chartView); this->resize(400, 300); this->show(); #endif #if 0 /* * AreaChart Example */ QLineSeries *series0 = new QLineSeries(); QLineSeries *series1 = new QLineSeries(); *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); QAreaSeries *series = new QAreaSeries(series0, series1); series->setName("Batman"); QPen pen(0x059605); pen.setWidth(3); series->setPen(pen); QChart *chart = new QChart(); chart->addSeries(series); chart->setTitle("Simple areachart example"); chart->createDefaultAxes(); chart->axisX()->setRange(0, 20); chart->axisY()->setRange(0, 10); QChartView *chartView = new QChartView(chart); chartView->setRenderHint(QPainter::Antialiasing); this->setCentralWidget(chartView); this->setCentralWidget(chartView); this->resize(400, 300); this->show(); #endif #if 0 /* * QScatterChart Example */ 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(0, 6); series0->append(2, 4); series0->append(3, 8); series0->append(7, 4); series0->append(10, 5); *series1 << QPointF(1, 1) << QPointF(3, 3) << QPointF(7, 6) << QPointF(8, 3) << QPointF(10, 2); *series2 << QPointF(1, 5) << QPointF(4, 6) << QPointF(6, 3) << QPointF(9, 5); 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(400, 300); this->show(); #endif #if 0 /* * BarChart Example */ 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 << 1 << 2 << 3 << 4 << 5 << 6; *set1 << 5 << 0 << 0 << 4 << 0 << 7; *set2 << 3 << 5 << 8 << 13 << 8 << 5; *set3 << 5 << 6 << 7 << 3 << 4 << 5; *set4 << 9 << 7 << 5 << 3 << 1 << 2; 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(400, 300); this->show(); #endif #if 0 /* * Piechart Example */ QPieSeries *series = new QPieSeries(); series->append("Jane", 1); series->append("Joe", 2); series->append("Andy", 3); series->append("Barbara", 4); series->append("Axel", 5); QPieSlice *slice = series->slices().at(1); slice->setExploded(); slice->setLabelVisible(); slice->setPen(QPen(Qt::darkGreen, 2)); 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(400, 300); this->show(); #endif } MainWindow::~MainWindow() { delete ui; }
还有一些图形及主题等设置，后续待补充。
4 其它
（1）如何在QWidget中绘制QCharts
上面的代码中都是在QMainWindow中绘制的QCharts，但如果我们要在QWidget中绘制QCharts，那么如何实现呢？
方式一：
可选择的解决方法：在ui中拖一个水平布局，把chartView放到水平布局。
测试代码：
Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) { ui->setupUi(this); /* * BarChart Example */ 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 << 1 << 2 << 3 << 4 << 5 << 6; *set1 << 5 << 0 << 0 << 4 << 0 << 7; *set2 << 3 << 5 << 8 << 13 << 8 << 5; *set3 << 5 << 6 << 7 << 3 << 4 << 5; *set4 << 9 << 7 << 5 << 3 << 1 << 2; 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); ui->horizontalLayout->addWidget(chartView); }运行测试：
这种方式每次是在水平布局中添加一个QWidget，有时候不太好用。
方式二：
将QWidget提升为QChartView。
在代码中直接使用下面的代码就可以显示了：
ui->widget_factory->setChart(chart); ui->widget_factory->show();
（2）如何在柱状图中顶端带数字显示
只需要添加下面两句代码：
series->setLabelsPosition(QAbstractBarSeries::LabelsInsideEnd); series->setLabelsVisible(true);
以上就是Qt绘制图表的实现的详细内容，更多请关注0133技术站其它相关文章！
