QT 动态实时曲线

1.首先在工程文件中加入

QT      += charts

2. .h文件

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QPen>
#include <QPainter>
#include <QtSvg/QSvgWidget>
#include <QtSvg/QSvgRenderer>
#include <QMouseEvent>

#include <QtCharts>
using namespace QtCharts;
namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private slots:
protected:
    void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE;
private:
    Ui::Widget *ui;
    void dataReceived(int value);
    int timerId;
    int maxSize;  // data 最多存储 maxSize 个元素
    int maxX;
    int maxY;
    QList<double> data; // 存储业务数据的 list
    QChart *chart;
    QChartView *chartView;
    QSplineSeries *splineSeries;
    QScatterSeries *scatterSeries;


};

#endif // WIDGET_H

3..cpp文件

#include "widget.h"
#include "ui_widget.h"
#include <QDebug>
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
  ui->setupUi(this);
  maxSize = 31; // 只存储最新的 31 个数据
  maxX = 300;
  maxY = 100;
  splineSeries = new QSplineSeries();
  scatterSeries = new QScatterSeries();
  scatterSeries->setMarkerSize(8);


  chart = new QChart();
  chart->addSeries(splineSeries);
  chart->addSeries(scatterSeries);
  chart->legend()->hide();
  chart->setTitle("实时动态曲线");
  chart->createDefaultAxes();
  chart->axisX()->setRange(0, 300);
  chart->axisY()->setRange(0, maxY);
  chartView = new QChartView(chart);

  QValueAxis *axisx = new QValueAxis;
  axisx->setGridLineVisible(false);
  axisx->setTitleText("sample time(s)");
  chartView->chart()->setAxisX(axisx, splineSeries);

  QValueAxis *axisy = new QValueAxis;
  axisy->setGridLineVisible(false);
  axisy->setTitleText("height(meter)");
  chartView->chart()->setAxisY(axisy,splineSeries);

  chartView->setRenderHint(QPainter::Antialiasing);


  QHBoxLayout *layout = new QHBoxLayout();
  layout->setContentsMargins(0, 0, 0, 0);
  layout->addWidget(chartView);
  setLayout(layout);
  timerId = startTimer(200);
  qsrand(QDateTime::currentDateTime().toTime_t());
}

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

void Widget::timerEvent(QTimerEvent *event) {
    // 产生一个数据，模拟不停的接收到新数据
    if (event->timerId() == timerId) {
        int newData = qrand() % (maxY + 1);
        dataReceived(newData);
    }
}

void Widget::dataReceived(int value) {
    data << value;
    // 数据个数超过了最大数量，则删除所有数据，从头开始。
    while (data.size() > maxSize) {
        data.clear();

    }
    // 界面被隐藏后就没有必要绘制数据的曲线了
    if (isVisible()) {
        splineSeries->clear();
        scatterSeries->clear();
        int dx = maxX / (maxSize-1);
        for (int i = 0; i < data.size(); ++i) {
            splineSeries->append(i*dx, data.at(i));
            scatterSeries->append(i*dx, data.at(i));
        }
    }
}

实现结果