QT简单曲线图绘制（基于QChart）

本例指定一系列离散点，可绘制曲线图，并可将图表嵌入QWidget中
效果如下：

本例曲线图绘制使用QT的QChart模块实现（QT5.7及其以上版本才有此功能），自行封装了Chart类，
调用如下：

.pro工程文件：

#-------------------------------------------------
#
# Project created by QtCreator 2020-08-12T20:05:22
#
#-------------------------------------------------

QT       += core gui
QT       += charts

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = QCharts_Test
TEMPLATE = app

DEFINES += QT_DEPRECATED_WARNINGS

SOURCES += \
        main.cpp \
        mainwindow.cpp \
    chart.cpp

HEADERS += \
        mainwindow.h \
    chart.h

FORMS += \
        mainwindow.ui

mainwindow.h文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 
#include "chart.h"

namespace Ui {
     
class MainWindow;
}

class MainWindow : public QMainWindow
{
     
    Q_OBJECT
    Chart *chart;
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    void initChart();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

mainwindow.cpp文件：

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

MainWindow::~MainWindow()
{
     
    delete ui;
}
//初始化图表
void MainWindow::initChart()
{
     
    //设置表头
    chart = new Chart(this,"历史数据");
    //设置坐标系
    chart->setAxis("X轴",0,100,11, "Y轴",0,20,11);
    //设置离散点数据
    QList<QPointF> pointlist = {
     QPointF(0,1), QPointF(10,2), QPointF(20,4), QPointF(30,8), QPointF(40,16), \
                                QPointF(50,16), QPointF(60,8), QPointF(70,4), QPointF(80,2), QPointF(90,1),};
    //绘制
    chart->buildChart(pointlist);
    //为MainWindow的centralWidget添加一个布局
    QHBoxLayout *pHLayout = new QHBoxLayout(ui->centralWidget);
    //将chart添加到布局中
    pHLayout->addWidget(chart);
}

最后是Chart类的实现：

chart.h

#ifndef CHART_H
#define CHART_H

#include 
#include 
#include 
#include 
#include 

QT_CHARTS_USE_NAMESPACE
class Chart : public QWidget
{
     
    Q_OBJECT
    QChart *qchart;
    QChartView *chartview;
    QSplineSeries *series;

    QHBoxLayout *layout;
    QValueAxis *axisX;
    QValueAxis *axisY;

    QString chartname;
    //坐标轴参数
    QString xname;
    qreal xmin;
    qreal xmax;
    int xtickc;
    QString yname;
    qreal ymin;
    qreal ymax;
    int ytickc;

public:
    Chart(QWidget* parent = 0, QString _chartname = "曲线图");
    ~Chart(){
     }
    void setAxis(QString _xname, qreal _xmin, qreal _xmax, int _xtickc, \
                 QString _yname, qreal _ymin, qreal _ymax, int _ytickc);
    void buildChart(QList<QPointF> pointlist);

};
#endif // CHART_H

chart.cpp

#include "chart.h"

Chart::Chart(QWidget* parent, QString _chartname){
     
    setParent(parent);
    chartname = _chartname;
    series = new QSplineSeries(this);
    qchart = new QChart;
    chartview = new QChartView(qchart);
    layout = new QHBoxLayout(this);
    axisX = new QValueAxis(this);
    axisY = new QValueAxis(this);
    //在ui里面添加了一个Widget并把曲线图添加进去
    layout->addWidget(chartview);
    setLayout(layout);
    chartview->setRenderHint(QPainter::Antialiasing);//防止图形走样
}

void Chart::setAxis(QString _xname, qreal _xmin, qreal _xmax, int _xtickc, \
             QString _yname, qreal _ymin, qreal _ymax, int _ytickc){
     
    xname = _xname; xmin = _xmin; xmax = _xmax; xtickc = _xtickc;
    yname = _yname; ymin = _ymin; ymax = _ymax; ytickc = _ytickc;

    axisX->setRange(xmin, xmax);    //设置范围
    axisX->setLabelFormat("%u");   //设置刻度的格式
    /************************************
        %u 无符号十进制整数
        %s 字符串
        %c 一个字符
        %d 有符号十进制整数
        %e 浮点数、e-记数法
        %f 浮点数、十进制记数法
        %s 字符串
    ****************************************/
        axisX->setGridLineVisible(true);   //网格线可见
        axisX->setTickCount(xtickc);       //设置多少个大格
        axisX->setMinorTickCount(1);   //设置每个大格里面小刻度线的数目
        axisX->setTitleText(xname);  //设置描述
        axisY->setRange(ymin, ymax);
        axisY->setLabelFormat("%u");
        axisY->setGridLineVisible(true);
        axisY->setTickCount(ytickc);
        axisY->setMinorTickCount(1);
        axisY->setTitleText(yname);
        qchart->addAxis(axisX, Qt::AlignBottom); //下：Qt::AlignBottom  上：Qt::AlignTop
        qchart->addAxis(axisY, Qt::AlignLeft);   //左：Qt::AlignLeft    右：Qt::AlignRight
}

void Chart::buildChart(QList<QPointF> pointlist)
{
     
    //创建数据源
    series->setPen(QPen(Qt::blue,3,Qt::SolidLine));
    series->clear();
    for(int i=0; i<pointlist.size();i++)
        series->append(pointlist.at(i).x(), pointlist.at(i).y());

    qchart->setTitle(chartname);
    qchart->setAnimationOptions(QChart::SeriesAnimations);//设置曲线动画模式
    qchart->legend()->hide(); //隐藏图例
    qchart->addSeries(series);//输入数据
    qchart->setAxisX(axisX, series);
    qchart->setAxisY(axisY, series);
}