头文件

#include <QWidget>
#include <QTimer>
#include <QtCharts/QChartView>//显示图表
#include <QtCharts/QLineSeries>//线系列
#include <QtCharts/QSplineSeries>
#include <QtCharts/QValueAxis>
#include <QDateTime>
#include <QDateTimeAxis>
#include<QDebug>

    QSplineSeries* mm_series;
 
    QStringList m_titles;
    QValueAxis m_axis;
    QDateTimeAxis AxisX;
    QValueAxis AxisY;
    
    qreal m_step;
    
    qreal m_x;
    qreal m_y;
    
    qreal min_y = 0;
    qreal max_y = 0;
    QDateTime start;
    QDateTime end;
    QTimer m_timer;

  chart.setTheme(QChart::ChartThemeDark);//设置系统主题
        chart.setTitle( QStringLiteral("飞参实时波形图") );//设置标题
        chart.setTitleFont(QFont("微软雅黑",10));
        //    chart.legend()->hide();
        chart.setAnimationOptions(QChart::SeriesAnimations); // 动画方式

        // x轴(时间轴方式)
        AxisX.setTitleText(QStringLiteral("时间(分:秒)")); // x轴显示标题
       // AxisX.setGridLineVisible(false); // 隐藏背景网格X轴框线
        AxisX.setFormat("mm:ss");  // x轴格式
        AxisX.setLabelsAngle(0); // x轴显示的文字倾斜角度
        AxisX.setTickCount(6); // 轴上点的个数
        start = QDateTime::currentDateTime();
        end = start.addSecs(110);
        AxisX.setRange(start, end); // 范围

        // y轴
        AxisY.setTitleText(QStringLiteral("数值")); // y轴显示标题
        //AxisY.setGridLineVisible(false); // 隐藏背景网格Y轴框线
        AxisY.setTickCount(6); // 轴上点的个数
        AxisY.setRange(0, 1000);

        // 图表视图
        chart.addAxis(&AxisX, Qt::AlignBottom); // 设置x轴位置
        chart.addAxis(&AxisY, Qt::AlignLeft);  // 设置y轴位置

        QChartView *chartView = new QChartView(&chart);
        chartView->setRenderHint(QPainter::Antialiasing);
        ui->verticalLayout->addWidget(chartView);

		//添加一条曲线
        mm_series = new QSplineSeries();
        mm_series->setName("name");
        chart.addSeries(mm_series);
        chart.legend()->setAlignment(Qt::AlignTop); //设置曲线对应标签
        // 线段
        mm_series->setPen(QPen(QColor(255,255,0), 2, Qt::SolidLine));// 设置线段pen
        mm_series->attachAxis(&AxisX); // 线段依附的x轴
        mm_series->attachAxis(&AxisY);

		//test专用
        connect(&m_timer, &QTimer::timeout, this, &chartwidget::on_timerevent);
        //  m_timer.start(100);

cpp

void chartwidget::append_data(QDateTime x, double y)
{
	//如果y值不在范围，则调整y
    if(y < min_y)
    {
        min_y = y;
        AxisY.setRange(min_y*0.9, max_y*1.1);
    }
    else if (y > max_y)
    {
        max_y = y;
        AxisY.setRange(min_y, max_y*1.1);
    }
  //如果x值不在范围，则调整x
    if(x > end)
    {
        end = end.addSecs(30);
        AxisX.setRange(start, end);
    }

  //把这个数值添加到曲线
    mm_series.append(x.toMSecsSinceEpoch(), y);

    QApplication::processEvents();
}

//添加一根曲线

void chartwidget::add_one_serie(QString name, QColor color)
{
    QSplineSeries* m_series = new QSplineSeries();
    m_series->setName(name);
    chart.addSeries(m_series);
    chart.legend()->setAlignment(Qt::AlignTop);                       //设置曲线对应标签
    // 线段
    m_series->setPen(QPen(color, 2, Qt::SolidLine));                 // 设置线段pen
    m_series->attachAxis(&AxisX);                                         // 线段依附的x轴
    m_series->attachAxis(&AxisY);
}

//弄个定时器测试用

void chartwidget::on_timerevent()
{
    qDebug()<<__FUNCTION__<<endl;
    QDateTime x = QDateTime::currentDateTime();

    if(x > end)
    {
        end = end.addSecs(30);
        AxisX.setRange(start, end);
    }
    for(int i = 0;i< 2;i++)
    {
       QDateTime x = start.addSecs(i);

       // 生成一个介于0到99之间的随机整数
       int randomNumber =QRandomGenerator::global()->bounded(1000);
       mm_series->append(x.toMSecsSinceEpoch(),randomNumber);
    }

    QApplication::processEvents();
}