QCustomPlot实现实时动态曲线

2019-11-10 18:08:21

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Qt4中，可以使用QCustompPlot来绘制曲线，QCustompPlot是一个第三方工具，可以到官网下载：http://www.qcustomplot.com/index.php/download

这里实现一个实时动态曲线图，用随机数作为实时数据，程序运行结果如下：

主机环境：fedora9，Qt4.7，Qtcreator 2.0.1使用Qtcreator 2.0.1新建一个工程，基类模板选择QMainWindow。将解压得到的QCustompPlot文件夹里面的头文件qcustomplot.h和源文件qcustomplot.cpp复制粘贴到工程文件夹下。在Qtcreator中，对着工程名右键，添加已有文件，将头文件qcustomplot.h和源文件qcustomplot.cpp都添加到工程中来。在界面上拖拽一个widget部件，然后升级成Qcustomplot，(参考：http://www.bubuko.com/infodetail-744744.html)部件名称改为customPlotmainwindow.h代码如下：

#ifndef MAINWINDOW_H#define MAINWINDOW_H#include <QMainWindow>#include <QTimer>#include "qcustomplot.h"namespace Ui { class MainWindow;}class MainWindow : public QMainWindow{ Q_OBJECTpublic: explicit MainWindow(QWidget *parent = 0); ~MainWindow(); //设置qcustomplot画图属性，实时 void setuPRealtimeDataDemo(QCustomPlot *customPlot);private slots: //添加实时数据槽 void realtimeDataSlot();private: Ui::MainWindow *ui; //定时器，周期调用realtimeDataSlot()槽，实现动态数据添加到曲线 QTimer dataTimer;};#endif // MAINWINDOW_Hmainwindow.cpp代码如下：#include "mainwindow.h"#include "ui_mainwindow.h"#include <QVector>#include <QTimer>#include <QTime>MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow){ ui->setupUi(this); setupRealtimeDataDemo(ui->customPlot); ui->customPlot->replot(); ui->checkBox_temp->setChecked(true); ui->checkBox_hui->setChecked(true);}MainWindow::~MainWindow(){ delete ui;}//画图初始化void MainWindow::setupRealtimeDataDemo(QCustomPlot *customPlot){//#if QT_VERSION < QT_VERSION_CHECK(4, 7, 0) //QMessageBox::critical(this, "", "You're using Qt < 4.7, the realtime data demo needs functions that are available with Qt 4.7 to work properly");//#endif //demoName = "Real Time Data Demo"; // include this section to fully disable antialiasing for higher performance: /* customPlot->setNotAntialiasedElements(QCP::aeAll); QFont font; font.setStyleStrategy(QFont::NoAntialias); customPlot->xAxis->setTickLabelFont(font); customPlot->yAxis->setTickLabelFont(font); customPlot->legend->setFont(font); */ customPlot->addGraph(); // blue line customPlot->graph(0)->setPen(QPen(Qt::blue)); customPlot->graph(0)->setName("temp"); //customPlot->graph(0)->setBrush(QBrush(QColor(240, 255, 200))); //customPlot->graph(0)->setAntialiasedFill(false); customPlot->addGraph(); // red line customPlot->graph(1)->setPen(QPen(Qt::red)); customPlot->graph(1)->setName("hui"); //customPlot->graph(0)->setChannelFillGraph(customPlot->graph(1)); customPlot->xAxis->setTickLabelType(QCPAxis::ltDateTime); customPlot->xAxis->setDateTimeFormat("hh:mm:ss"); customPlot->xAxis->setAutoTickStep(false); customPlot->xAxis->setTickStep(2); customPlot->axisRect()->setupFullAxesBox(); // make left and bottom axes transfer their ranges to right and top axes: //connect(customPlot->xAxis, SIGNAL(rangeChanged(QCPRange)), customPlot->xAxis2, SLOT(setRange(QCPRange))); //connect(customPlot->yAxis, SIGNAL(rangeChanged(QCPRange)), customPlot->yAxis2, SLOT(setRange(QCPRange))); // setup a timer that repeatedly calls MainWindow::realtimeDataSlot: connect(&dataTimer, SIGNAL(timeout()), this, SLOT(realtimeDataSlot())); dataTimer.start(0); // Interval 0 means to refresh as fast as possible customPlot->legend->setVisible(true);}void MainWindow::realtimeDataSlot(){ //key的单位是秒 double key = QDateTime::currentDateTime().toMSeCSSinceEpoch()/1000.0; qsrand(QTime::currentTime().msec() + QTime::currentTime().second() * 10000); //使用随机数产生两条曲线 double value0 = qrand() % 100; double value1 = qrand() % 80; if (ui->checkBox_temp->isChecked()) ui->customPlot->graph(0)->addData(key, value0);//添加数据1到曲线1 if (ui->checkBox_hui->isChecked()) ui->customPlot->graph(1)->addData(key, value1);//添加数据2到曲线2 //删除8秒之前的数据。这里的8要和下面设置横坐标宽度的8配合起来 //才能起到想要的效果，可以调整这两个值，观察显示的效果。 ui->customPlot->graph(0)->removeDataBefore(key-8); ui->customPlot->graph(1)->removeDataBefore(key-8); //自动设定graph(1)曲线y轴的范围，如果不设定，有可能看不到图像//也可以用ui->customPlot->yAxis->setRange(up,low)手动设定y轴范围 ui->customPlot->graph(0)->rescaleValueAxis(); ui->customPlot->graph(1)->rescaleValueAxis(true); //这里的8，是指横坐标时间宽度为8秒，如果想要横坐标显示更多的时间 //就把8调整为比较大到值，比如要显示60秒，那就改成60。 //这时removeDataBefore(key-8)中的8也要改成60，否则曲线显示不完整。 ui->customPlot->xAxis->setRange(key+0.25, 8, Qt::AlignRight);//设定x轴的范围 ui->customPlot->replot();}

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