這里實現一個實時動態曲線圖，用隨機數作為實時數據，程序運行結果如下：
主機環境：fedora9，Qt4.7，Qtcreator 2.0.1使用Qtcreator 2.0.1新建一個工程，基類模板選擇QMainWindow。將解壓得到的QCustompPlot文件夾里面的頭文件qcustomplot.h和源文件qcustomplot.cpp復制粘貼到工程文件夾下。在Qtcreator中，對著工程名右鍵，添加已有文件，將頭文件qcustomplot.h和源文件qcustomplot.cpp都添加到工程中來。在界面上拖拽一個widget部件，然后升級成Qcustomplot，(參考：http://www.bubuko.com/infodetail-744744.html)部件名稱改為customPlotmainwindow.h代碼如下：
#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(); //設置qcustomplot畫圖屬性，實時 void setuPRealtimeDataDemo(QCustomPlot *customPlot);private slots: //添加實時數據槽 void realtimeDataSlot();private: Ui::MainWindow *ui; //定時器，周期調用realtimeDataSlot()槽，實現動態數據添加到曲線 QTimer dataTimer;};#endif // MAINWINDOW_Hmainwindow.cpp代碼如下：#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;}//畫圖初始化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的單位是秒 double key = QDateTime::currentDateTime().toMSeCSSinceEpoch()/1000.0; qsrand(QTime::currentTime().msec() + QTime::currentTime().second() * 10000); //使用隨機數產生兩條曲線 double value0 = qrand() % 100; double value1 = qrand() % 80; if (ui->checkBox_temp->isChecked()) ui->customPlot->graph(0)->addData(key, value0);//添加數據1到曲線1 if (ui->checkBox_hui->isChecked()) ui->customPlot->graph(1)->addData(key, value1);//添加數據2到曲線2 //刪除8秒之前的數據。這里的8要和下面設置橫坐標寬度的8配合起來 //才能起到想要的效果，可以調整這兩個值，觀察顯示的效果。 ui->customPlot->graph(0)->removeDataBefore(key-8); ui->customPlot->graph(1)->removeDataBefore(key-8); //自動設定graph(1)曲線y軸的范圍，如果不設定，有可能看不到圖像//也可以用ui->customPlot->yAxis->setRange(up,low)手動設定y軸范圍 ui->customPlot->graph(0)->rescaleValueAxis(); ui->customPlot->graph(1)->rescaleValueAxis(true); //這里的8，是指橫坐標時間寬度為8秒，如果想要橫坐標顯示更多的時間 //就把8調整為比較大到值，比如要顯示60秒，那就改成60。 //這時removeDataBefore(key-8)中的8也要改成60，否則曲線顯示不完整。 ui->customPlot->xAxis->setRange(key+0.25, 8, Qt::AlignRight);//設定x軸的范圍 ui->customPlot->replot();}新聞熱點
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