pro

QT   +=  charts

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QChartView>
#include <QLineSeries>
#include <QTimer>
#include <QValueAxis>

QT_CHARTS_USE_NAMESPACE

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
private slots:
    void dealTimeOut();
private:
    Ui::MainWindow *ui;
    QLineSeries *m_series;
    QChartView *m_chartView;
    QChart *m_chart;
    QList<QPointF> m_points;
    QTimer *m_timer;
    QValueAxis *m_axisX;
    QValueAxis *m_axisY;
};

#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QValueAxis>
#include "QLineSeries"
#include "QValueAxis"
#include "QTimer"
#include "QTime"
#include "QList"
#include "qmath.h"
#include "QPointF"
#include "QDebug"

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

    m_chart = new QChart();
    m_chart->legend()->hide();
    m_chart->addSeries(m_series);
    m_axisX = new QValueAxis;
    m_axisX->setRange(0,20);
    m_axisY = new QValueAxis;
    m_axisY->setRange(0,20);
    m_chart->setAxisX(m_axisX,m_series);
    m_chart->setAxisY(m_axisY,m_series);

    m_chartView = new QChartView(m_chart);
    ui->verticalLayout->addWidget(m_chartView);

    m_timer = new QTimer();
    connect(m_timer,SIGNAL(timeout()),this,SLOT(dealTimeOut()));
    m_timer->start(1000);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::dealTimeOut()
{
    static int i = 0;
    static int j = 0;
    static int h = 0;

    QTime time;
    time= QTime::currentTime();
    qsrand(time.msec()+time.second()*1000);
    int n = qrand() % 10;    //产生10以内的随机数

    m_points.append(QPointF(i,n));
    m_series->replace(m_points);
    if(i > 10)
    {
        m_axisX->setRange(j++, 20+h++);//设置x坐标轴
        m_points.removeFirst();
    }
    i++;
}