本代码实现的功能：

1. 实时动态双曲线
2. 可以鼠标拖拽
3. 可以保留已经产生的数据
4. 随着鼠标的移动实时显示X、Y轴坐标

在.pro中

QT       += charts

在ChartView.h中

#ifndef __CHARTVIEW_H__

#define __CHARTVIEW_H__

#include 

#include 

QT_CHARTS_USE_NAMESPACE

class ChartView : public QChartView

{

public:

    ChartView(QChart *chart, QWidget *parent = 0);

protected:

    void keyPressEvent(QKeyEvent *event);

    void mousePressEvent(QMouseEvent *event);

    void mouseMoveEvent(QMouseEvent *event);

    void mouseReleaseEvent(QMouseEvent *event);

private:

    bool isClicking;

    int xOld;

    int yOld;

    QGraphicsSimpleTextItem* m_coordItem;

};

#endif /* __CHARTVIEW_H__ */

在ChartView.cpp中

#include "chartview.h"

ChartView::ChartView(QChart *chart, QWidget *parent) :

    QChartView(chart, parent),

    isClicking(false),

    xOld(0), yOld(0)

{

    setRubberBand(QChartView::RectangleRubberBand);

}

void ChartView::mousePressEvent(QMouseEvent *event)

{

    if (event->button() & Qt::LeftButton) {

        isClicking = true;

    } else if (event->button() & Qt::RightButton) {

        chart()->zoomReset();

    }

    QChartView::mousePressEvent(event);

}

void ChartView::mouseMoveEvent(QMouseEvent *event)

{

    int x, y;

    if (!m_coordItem)

    {

        m_coordItem = new QGraphicsSimpleTextItem(this->chart());

        m_coordItem->setZValue(5);

        m_coordItem->setPos(100, 60);

        m_coordItem->show();

    }

    const QPoint curPos = event->pos();

    QPointF curVal = this->chart()->mapToValue(QPointF(curPos));

    QString coordStr = QString("X = %1, Y = %2").arg(curVal.x()).arg(curVal.y());

    m_coordItem->setText(coordStr);

    if (isClicking) {

        if (xOld == 0 && yOld == 0) {

        } else {

            x = event->x() - xOld;

            y = event->y() - yOld;

            chart()->scroll(-x, y);

        }

        xOld = event->x();

        yOld = event->y();

        return;

    }

    QChartView::mouseMoveEvent(event);

}

void ChartView::mouseReleaseEvent(QMouseEvent *event)

{

    if (isClicking) {

        xOld = yOld = 0;

        isClicking = false;

    }

    /* Disable original right click event */

    if (!(event->button() & Qt::RightButton)) {

        QChartView::mouseReleaseEvent(event);

    }

}

void ChartView::keyPressEvent(QKeyEvent *event)

{

    switch (event->key()) {

    case Qt::Key_Left:

        chart()->scroll(-10, 0);

        break;

    case Qt::Key_Right:

        chart()->scroll(10, 0);

        break;

    case Qt::Key_Up:

        chart()->scroll(0, 10);

        break;

    case Qt::Key_Down:

        chart()->scroll(0, -10);

        break;

    default:

        keyPressEvent(event);

        break;

    }

}

在MainWindow.h中

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include 

#include "qmessagebox.h"

//QChart

#include 

using namespace QtCharts;

//定时器

#include 

#include "chartview.h"

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

    explicit MainWindow(QWidget *parent = 0);

    ~MainWindow();

private slots:

    void updata_plot();

    void on_pushButton_clicked();

    void on_pushButton_2_clicked();

private:

    //绘图定时器

    QTimer *timer_plot;

    //曲线

    QSplineSeries* line;

    QSplineSeries* line1;

    //曲线点的最大数量

    int line_max = 100;

    int a = 1;

    int b = 2;

    int c = 0;

    ChartView *chartView;

    //绘图变量和坐标

    QChart* chart;

    QValueAxis *axisX;

    QValueAxis *axisY;

    void initchar();

private:

    Ui::MainWindow *ui;

};

#endif // MAINWINDOW_H

在MainWindow.cpp中

#include "mainwindow.h"

#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

    //将变量实例化

    timer_plot = new QTimer(this);

    connect(timer_plot,SIGNAL(timeout()),this,SLOT(updata_plot()));

    initchar();

    axisX = new QValueAxis(this);

    axisY = new QValueAxis(this);

    this->setWindowTitle("速度对比");

    timer_plot->start(50);

}

//图像更新函数

void MainWindow::updata_plot()

{

    QVector list;

    QVector newlist;

    QVector list1;

    QVector newlist1;

    list = line->pointsVector();//获取现在图中列表

    if (list.size() < line_max)

    {

        //保持原来

        newlist = list;

    }

    else

    {

        //错位移动

        newlist = list;

        c = c + 1;

        chart->axisX()->setRange(0+c,100+c);

    }

    a = a+2;

    newlist.append(QPointF(newlist.size(),a));//最后补上新的数据

    line->replace(newlist);//替换更新

    line->setName("期望速度");//设置曲线名称

    line->setPen(QColor(255, 0, 0));//设置曲线颜色

    line->setUseOpenGL(true);//openGl 加速

    list1 = line1->pointsVector();//获取现在图中列表

    if (list1.size() < line_max)

    {

        //保持原来

        newlist1 = list1;

    }

    else

    {

        //错位移动

        newlist1 = list1;

    }

    b = b+3;

    newlist1.append(QPointF(newlist1.size(),b));//最后补上新的数据

    line1->replace(newlist1);//替换更新

    line1->setName("当前速度");//设置曲线名称

    line1->setPen(QColor(100, 100, 0));//设置曲线颜色

    line1->setUseOpenGL(true);//openGl 加速

}

MainWindow::~MainWindow()

{

    delete ui;

}

void MainWindow::on_pushButton_clicked()

{

    timer_plot->start(50);//启动定时器

}

void MainWindow::on_pushButton_2_clicked()

{

    timer_plot->stop();//关闭定时器

}

void MainWindow::initchar()

{

    line = new QSplineSeries(this);

    chart = new QChart();

    chart->addSeries(line);

    line1 = new QSplineSeries(this);

    chart->addSeries(line1);

    chart->removeSeries(line1);

    chart->addSeries(line1);

    chart->setTitle("速度对比");//设置图标标题

    chart->removeSeries(line);

    chart->addSeries(line);

    chart->createDefaultAxes();//设置坐标轴

    chart->axisX()->setRange(0,100);

    chart->axisY()->setRange(0,1500);

//    chart->legend()->hide();

    chartView = new ChartView(chart);

    chartView->setRenderHint(QPainter::Antialiasing);

    ui->horizontalLayout_2->addWidget(chartView);

}

在MainWindow.ui中