Qt QChart，利用QChart绘制动态曲线

Qt QChart，利用QChart绘制动态曲线

2017年07月11日 20:18:27 wudroid 阅读数 21511

 版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.youkuaiyun.com/HiccupHiccup/article/details/74996618

这是一个简单的demo，在更新数据的时候我采用了官方中audio这个example的方式。

 

效果图

 

程序

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运行环境 ：

Qt Creator 4.2.1

Based on Qt 5.8.0 (MSVC 2015, 32 bit)

 

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QtChartsTest.pro

这个文件中唯一需要添加的是

QT += charts

其他可以不看

 

1. #-------------------------------------------------

2. #

3. # Project created by QtCreator 2017-07-11T10:12:57

4. #

5. #-------------------------------------------------

6.  

7. QT += core gui

8.  

9. greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

10.  

11. TARGET = QtChartsTest

12. TEMPLATE = app

13.  

14. # The following define makes your compiler emit warnings if you use

15. # any feature of Qt which as been marked as deprecated (the exact warnings

16. # depend on your compiler). Please consult the documentation of the

17. # deprecated API in order to know how to port your code away from it.

18. DEFINES += QT_DEPRECATED_WARNINGS

19.  

20. # You can also make your code fail to compile if you use deprecated APIs.

21. # In order to do so, uncomment the following line.

22. # You can also select to disable deprecated APIs only up to a certain version of Qt.

23. #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0

24.  
25.  

26. SOURCES += main.cpp\

27. mainwindow.cpp

28.  

29. HEADERS += mainwindow.h

30.  

31. FORMS += mainwindow.ui

32.  

33. QT += charts

 

 

mainwindow.h

这个文件声明了一个定时器的槽和一个获得数据的方法

 

1. #ifndef MAINWINDOW_H

2. #define MAINWINDOW_H

3.  

4. #include <QMainWindow>

5.  

6. namespace Ui {

7. class MainWindow;

8. }

9.  

10. class MainWindow : public QMainWindow

11. {

12. Q_OBJECT

13.  

14. public:

15. explicit MainWindow(QWidget *parent = 0);

16. ~MainWindow();

17. protected:

18. void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE;

19. private:

20. Ui::MainWindow *ui;

21. double getData(double time);

22.  

23. };

24.  

25. #endif // MAINWINDOW_H

mainwindow.cpp

 

主程序中配置好Qchart，QLineSeries是用来存放数据。更新的工作放在定时器的槽中。其中

 

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

采用openGL加速，绘图速度加快

 

1. #include "mainwindow.h"

2. #include "ui_mainwindow.h"

3. #include "QtCharts/QChart"

4. #include "QLineSeries"

5. #include "QValueAxis"

6. #include "QTimer"

7. #include "QTime"

8. #include "QList"

9. #include "qmath.h"

10. #include "QPointF"

11. #include "QDebug"

12.  

13. //#include <QtCharts/QChartGlobal>

14. #include "QChartView"

15. QT_CHARTS_USE_NAMESPACE

16. QChart *m_chart;

17. QLineSeries *m_series;

18. //QList<double> dataList;//存储业务数据

19. int maxSize = 5000;

20.  

21. //QTimer updateTimer;

22. int timeId;

23. MainWindow::MainWindow(QWidget *parent) :

24. QMainWindow(parent),//默认初始化？

25. ui(new Ui::MainWindow)

26. {

27. ui->setupUi(this);

28.  

29. m_chart = new QChart;

30. QChartView *chartView = new QChartView(m_chart);

31. // v.setRubberBand(QChartView::HorizontalRubberBand);

32. chartView->setRubberBand(QChartView::RectangleRubberBand);

33. // chartView->setRubberBand();

34.  

35. m_series = new QLineSeries;

36. m_chart->addSeries(m_series);

37.  

38. for(int i=0;i<maxSize;++i){

39. m_series->append(i,0);

40. }

41. m_series->setUseOpenGL(true);//openGl 加速

42. qDebug()<<m_series->useOpenGL();

43.  

44. QValueAxis *axisX = new QValueAxis;

45. axisX->setRange(0,maxSize);

46. axisX->setLabelFormat("%g");

47. axisX->setTitleText("axisX");

48.  

49. QValueAxis *axisY = new QValueAxis;

50. axisY->setRange(-1.5,1.5);

51. axisY->setTitleText("axisY");

52.  

53. m_chart->setAxisX(axisX,m_series);

54. m_chart->setAxisY(axisY,m_series);

55. m_chart->legend()->hide();

56. m_chart->setTitle("demo");

57.  

58. QVBoxLayout *layout = ui->verticalLayout;

59. layout->addWidget(chartView);

60. timeId = startTimer(30);

61. }

62.  
63.  

64. double MainWindow::getData(double time){

65.  

66. double s = qCos( time * M_PI * 2 ) ;

67. return s;

68. }

69.  

70. void MainWindow::timerEvent(QTimerEvent *event){

71. if(event->timerId()==timeId){//定时器到时间,//模拟数据填充

72. static QTime dataTime(QTime::currentTime());

73. long int eltime = dataTime.elapsed();

74. static int lastpointtime = 0;

75. int size = (eltime - lastpointtime);//数据个数

76. qDebug()<<"size-->"<<size;

77. if(isVisible()){

78. QVector<QPointF> oldPoints = m_series->pointsVector();//Returns the points in the series as a vector

79. QVector<QPointF> points;

80.  

81. for(int i=size;i<oldPoints.count();++i){

82. points.append(QPointF(i-size ,oldPoints.at(i).y()));//替换数据用

83. }

84. qint64 sizePoints = points.count();

85. for(int k=0;k<size;++k){

86. points.append(QPointF(k+sizePoints,getData((((double)lastpointtime+k+1)/1000))));

87. }

88. m_series->replace(points);

89. lastpointtime = eltime;

90. }

91. }

92. }

93. MainWindow::~MainWindow()

94. {

95. delete ui;

96. }

 

 

main.cpp

没什么好说的

 

1. #include "mainwindow.h"

2. #include <QApplication>

3.  

4. int main(int argc, char *argv[])

5. {

6. QApplication a(argc, argv);

7. MainWindow w;

8. w.show();

9.  

10. return a.exec();

11. }

 

 

mainwindow.ui

这个里自己放一个vertical Layout

 

这只是我根据别人的程序写的简单demo，有问题欢迎讨论。
 

demo文件：

链接：http://pan.baidu.com/s/1cKXtIQ 密码：5sm2