QT 动态实时曲线

1.首先在工程文件中加入

QT      += charts

2. .h文件

 1 #ifndef WIDGET_H
 2 #define WIDGET_H
 3 
 4 #include <QWidget>
 5 #include <QPen>
 6 #include <QPainter>
 7 #include <QtSvg/QSvgWidget>
 8 #include <QtSvg/QSvgRenderer>
 9 #include <QMouseEvent>
10 
11 #include <QtCharts>
12 using namespace QtCharts;
13 namespace Ui {
14 class Widget;
15 }
16 
17 class Widget : public QWidget
18 {
19     Q_OBJECT
20 
21 public:
22     explicit Widget(QWidget *parent = 0);
23     ~Widget();
24 
25 private slots:
26 protected:
27     void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE;
28 private:
29     Ui::Widget *ui;
30     void dataReceived(int value);
31     int timerId;
32     int maxSize;  // data 最多存储 maxSize 个元素
33     int maxX;
34     int maxY;
35     QList<double> data; // 存储业务数据的 list
36     QChart *chart;
37     QChartView *chartView;
38     QSplineSeries *splineSeries;
39     QScatterSeries *scatterSeries;
40 
41 
42 };
43 
44 #endif // WIDGET_H

3..cpp文件

 1 #include "widget.h"
 2 #include "ui_widget.h"
 3 #include <QDebug>
 4 Widget::Widget(QWidget *parent) :
 5     QWidget(parent),
 6     ui(new Ui::Widget)
 7 {
 8   ui->setupUi(this);
 9   maxSize = 31; // 只存储最新的 31 个数据
10   maxX = 300;
11   maxY = 100;
12   splineSeries = new QSplineSeries();
13   scatterSeries = new QScatterSeries();
14   scatterSeries->setMarkerSize(8);
15 
16 
17   chart = new QChart();
18   chart->addSeries(splineSeries);
19   chart->addSeries(scatterSeries);
20   chart->legend()->hide();
21   chart->setTitle("实时动态曲线");
22   chart->createDefaultAxes();
23   chart->axisX()->setRange(0, 300);
24   chart->axisY()->setRange(0, maxY);
25   chartView = new QChartView(chart);
26 
27   QValueAxis *axisx = new QValueAxis;
28   axisx->setGridLineVisible(false);
29   axisx->setTitleText("sample time(s)");
30   chartView->chart()->setAxisX(axisx, splineSeries);
31 
32   QValueAxis *axisy = new QValueAxis;
33   axisy->setGridLineVisible(false);
34   axisy->setTitleText("height(meter)");
35   chartView->chart()->setAxisY(axisy,splineSeries);
36 
37   chartView->setRenderHint(QPainter::Antialiasing);
38 
39 
40   QHBoxLayout *layout = new QHBoxLayout();
41   layout->setContentsMargins(0, 0, 0, 0);
42   layout->addWidget(chartView);
43   setLayout(layout);
44   timerId = startTimer(200);
45   qsrand(QDateTime::currentDateTime().toTime_t());
46 }
47 
48 Widget::~Widget()
49 {
50     delete ui;
51 }
52 
53 void Widget::timerEvent(QTimerEvent *event) {
54     // 产生一个数据，模拟不停的接收到新数据
55     if (event->timerId() == timerId) {
56         int newData = qrand() % (maxY + 1);
57         dataReceived(newData);
58     }
59 }
60 
61 void Widget::dataReceived(int value) {
62     data << value;
63     // 数据个数超过了最大数量，则删除所有数据，从头开始。
64     while (data.size() > maxSize) {
65         data.clear();
66 
67     }
68     // 界面被隐藏后就没有必要绘制数据的曲线了
69     if (isVisible()) {
70         splineSeries->clear();
71         scatterSeries->clear();
72         int dx = maxX / (maxSize-1);
73         for (int i = 0; i < data.size(); ++i) {
74             splineSeries->append(i*dx, data.at(i));
75             scatterSeries->append(i*dx, data.at(i));
76         }
77     }
78 }

实现结果