qwt画实时曲线的小demo

#include "qwt.h" #include "qwt_plot.h" #include "qwt_scale_draw.h" #include "qwt_plot_layout.h" #include "qwt_plot_canvas.h" #include "qwt_plot_curve.h" #include "QTextCodec" #include "qwt_plot_grid.h" #include "qwt_symbol.h" #include <QVBoxLayout> #define TIMER_INTERVAL 2 class TimeScaleDrawR: public QwtScaleDraw { public: TimeScaleDrawR(const QDateTime &base): baseTime(base) { } virtual QwtText label(double v) const { QDateTime upTime = baseTime.addSecs((int)v); return upTime.toString("hh:mm:ss"); } private: QDateTime baseTime; }; qwt::qwt(QWidget *parent, Qt::WFlags flags) : QMainWindow(parent, flags) { ui.setupUi(this); // QVBoxLayout* vLayout = new QVBoxLayout(this); // m_plot = new QwtPlot(QwtText("实时曲线图"),this); m_plot->setCanvasBackground(QBrush(Qt::white)); //vLayout->addWidget(m_plot); m_plot->setGeometry(0,0,600,400); test(1); } qwt::~qwt() { } int qwt::test( int a ) { m_timeAreaWidth = 60; m_plot->setAxisScale(QwtPlot::yLeft, 0, 100); m_plot->setAxisTitle(QwtPlot::yLeft, "左边"); m_baseTime = QDateTime::currentDateTime(); m_plot->setAxisScaleDraw(QwtPlot::xBottom, new TimeScaleDrawR(m_baseTime)); m_plot->setAxisScale(QwtPlot::xBottom, 0, m_timeAreaWidth); m_plot->setAxisTitle(QwtPlot::xBottom,"底下"); m_plot->setAxisLabelRotation(QwtPlot::xBottom, -50.0); m_plot->setAxisLabelAlignment(QwtPlot::xBottom, Qt::AlignLeft|Qt::AlignBottom); m_plot->plotLayout()->setAlignCanvasToScales(true); m_plot->canvas()->setBorderRadius(10); //m_plot->setGeometry(QRect(20, 70, 1050, 570)); //m_plot->setCanvasBackground(QBrush(Qt:lightGray)); QwtPlotGrid* grid = new QwtPlotGrid(); grid->enableXMin(true); grid->enableYMin(true); grid->setMajPen(QPen(Qt::darkGray,0,Qt::DotLine)); grid->setMinPen(QPen(Qt::lightGray,0,Qt::DotLine)); grid->attach(m_plot); //resize(2110, 1660); for ( int i = 0; i < m_timeAreaWidth; i++ ) m_timeData[i] =-i; /*m_timerId = */startTimer(TIMER_INTERVAL*1000); // 1 second m_curve = new QwtPlotCurve("测试"); m_curve->setPen(QColor(Qt::blue)); m_curve->setRenderHint(QwtPlotItem::RenderAntialiased); m_curve->attach(m_plot); /////////////////////// m_curve->setSymbol(new QwtSymbol(QwtSymbol::Cross, Qt::NoBrush, QPen(Qt::blue), QSize(5, 5) ) ); m_plot->replot(); return 0; } void qwt::timerEvent( QTimerEvent *e ) { qint64 timeVal = (QDateTime::currentDateTime().toMSecsSinceEpoch()-m_baseTime.toMSecsSinceEpoch())/1000; QPointF pt; if(m_vp.size() >= m_timeAreaWidth) { m_vp.pop_front(); } pt.setX(timeVal); pt.setY(rand()%100); m_vp.append(pt); qint64 k = timeVal; for ( int j = 0; j < m_timeAreaWidth; j++ ) { m_timeData[j] = k--; } m_plot->setAxisScale(QwtPlot::xBottom, m_timeData[m_timeAreaWidth - 1 ], m_timeData[0]); m_curve->setSamples(m_vp); m_plot->replot(); }