Qt繪制圖表的實現
1 簡介
使用Qt的charts模塊來繪制圖表，案例來自Qt自帶的demo。
charts模塊簡介：Qt Chars模塊提供瞭一系列容易使用的圖表組件。需要使用charts組件時，需要導入Qt Charts模塊，通過如下方式：QT += charts
在安裝Qt Creator的時候，需要勾選上這個模塊，不然是不能使用的。
2 Qt Charts總覽
Qt Chars支持繪制：坐標圖、柱狀圖、折線圖、餅圖、曲線圖、散點圖等。
3 測試及說明
首先創建一個工程，繼承至MainWindow組件。
（1）繪制折線圖
折線圖通過線段展示一系列相關聯的點。
使用的類：QLineSeries
測試代碼：
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
/*
* LineChart Example
*/
//添加一個QLineSeries實例
QLineSeries *lineseries = new QLineSeries();
//添加數據（點），有兩種方式
lineseries->append(0, 6); //參數分別為橫縱坐標
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);
//添加一個QChart實例，為瞭展示數據
QChart *chart = new QChart();
chart->legend()->hide(); //隱藏圖例
chart->addSeries(lineseries);
chart->createDefaultAxes();
chart->setTitle("Simple line chart example");
//添加一個QChartView圖例
QChartView *chartView = new QChartView(chart);
chartView->setRenderHint(QPainter::Antialiasing); //呈現方式
//顯示
this->setCentralWidget(chartView);
this->setCentralWidget(chartView);
this->resize(400, 300);
this->show();
}
運行測試：
（2）繪制曲線圖
使用的類：QSplineSeries
測試代碼：
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();
運行測試：
（3）繪制面積圖
使用的類：QAreaSeries
測試代碼：
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();
運行測試：
（4）繪制散點圖
使用的類：QScatterSeries
測試代碼：
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();
運行測試：
（5）繪制柱狀圖
使用的類：QBarSeries
測試代碼：
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();
運行測試：
（6）繪制餅圖
使用的類：QPieSeries
測試代碼：
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();
運行測試：
完整的測試代碼：
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtCharts>
#include <QPainter>
#include <QPainterPath>
#include <QtMath>
#include <QImage>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
#if 0
/*
* LineChart Example
*/
//添加一個QLineSeries實例
QLineSeries *lineseries = new QLineSeries();
//添加數據（點），有兩種方式
lineseries->append(0, 6); //參數分別為橫縱坐標
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);
//添加一個QChart實例，為瞭展示數據
QChart *chart = new QChart();
chart->legend()->hide(); //隱藏圖例
chart->addSeries(lineseries);
chart->createDefaultAxes();
chart->setTitle("Simple line chart example");
//添加一個QChartView圖例
QChartView *chartView = new QChartView(chart);
chartView->setRenderHint(QPainter::Antialiasing); //呈現方式
//顯示
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;
}
還有一些圖形及主題等設置，後續待補充。
4 其它
（1）如何在QWidget中繪制QCharts
上面的代碼中都是在QMainWindow中繪制的QCharts，但如果我們要在QWidget中繪制QCharts，那麼如何實現呢？
方式一：
可選擇的解決方法：在ui中拖一個水平佈局，把chartView放到水平佈局。
測試代碼：
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);
}
運行測試：
這種方式每次是在水平佈局中添加一個QWidget，有時候不太好用。
方式二：
將QWidget提升為QChartView。
在代碼中直接使用下面的代碼就可以顯示瞭：
ui->widget_factory->setChart(chart); ui->widget_factory->show();
（2）如何在柱狀圖中頂端帶數字顯示
隻需要添加下面兩句代碼：
series->setLabelsPosition(QAbstractBarSeries::LabelsInsideEnd); series->setLabelsVisible(true);
到此這篇關於Qt繪制圖表的實現的文章就介紹到這瞭,更多相關Qt繪制圖表內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet！
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