QChart画实时曲线时，X轴显示时间的问题

[mickey35]

参考各位大神的教程以及Qt官方的《Audio example》例程，用Qchart画了一个实时曲线，就是下面这个


想把X轴的坐标换成实时时间，就像下面这样


画实时曲线的大致流程是定义一个QLineSeries放在QChart里面，在收到数据后，定义一个QVector<QPointF>接收数据作为y坐标，把实时时间now.toMSecsSinceEpoch()作为x坐标，然后把QLineSeries中点替换成这个QVector<QPointF>，但是实时时间now.toMSecsSinceEpoch()是个quint64的类型，放到QPointF中好像不行，各位大神有没有什么解决的办法？或者有没有其他画出实时曲线同时在x坐标轴上实时显示时间的方法？

以下是接收到数据时的处理代码：

void RealTimeCurveQChartWidget::dataReceived(int value)
{
    data << value;
    // 数据个数超过了最大数量，则删除最先接收到的数据，实现曲线向前移动
    while (data.size() > maxSize)
    {
        data.removeFirst();
    }
    //QVector<QPointF> oldPoints = splineSeries->pointsVector();
    QVector<QPointF> points;

    // 界面被隐藏后就没有必要绘制数据的曲线了
    if (isVisible())
    {
        //splineSeries->clear();
        //scatterSeries->clear();
        double range = 0,max = 0,min = 0;
        foreach (double val, data)
        {
            if(val > max)   max = val;
            if(val < min)   min = val;
        }
        range = max - min;
        chart->axisY()->setRange(min - (range/10), max + (range/10));

        QDateTime now = QDateTime::currentDateTime();

        QDateTimeAxis *time_axis = new QDateTimeAxis;
        time_axis->setRange(now.addMSecs(-100*maxSize),now);
        time_axis->setTickCount(5);
        time_axis->setFormat("hh:mm:ss");
        chart->setAxisX(time_axis);

        int dx = 100;/* 100ms */
        chart->axisX()->setRange(0,dx*maxSize);
        int less = maxSize - data.size();
        for (int i = 0; i < data.size(); ++i)
        {
            //splineSeries->append(now.addMSecs(-100*50).toMSecsSinceEpoch() + 100*i, data.at(i));
//            splineSeries->append(now.addMSecs(-100*maxSize).toMSecsSinceEpoch() + less*dx+i*dx, data.at(i));
//            scatterSeries->append(now.addMSecs(-100*maxSize).toMSecsSinceEpoch() + less*dx+i*dx, data.at(i));
            //splineSeries->append(less*dx+i*dx, data.at(i));
            points.append(QPointF((qreal)now.addMSecs(-100*maxSize).toMSecsSinceEpoch() + less*dx+i*dx, data.at(i)));
            //points.append(QPointF(less*dx+i*dx, data.at(i)));
            //scatterSeries->append(less*dx+i*dx, data.at(i));
        }

        splineSeries->replace(points);
//        splineSeries->attachAxis(time_axis);
//        scatterSeries->attachAxis(time_axis);
    }
}

[mickey35]

已经改用Qcustomplot了

[SealedGhost]

Qt帮助文档中 QDateTimeAxis Class 有一个例程：

 QLineSeries *series = new QLineSeries;

  QDateTime xValue;
  xValue.setDate(QDate(2012, 1 , 18));
  xValue.setTime(QTime(9, 34));
  qreal yValue = 12;
  series->append(xValue.toMSecsSinceEpoch(), yValue);

  xValue.setDate(QDate(2013, 5 , 11));
  xValue.setTime(QTime(11, 14));
  qreal yValue = 22;
  series->append(xValue.toMSecsSinceEpoch(), yValue);

[多空俊秀]

将原轴删除，再加上时间轴就OK了 即使用chart->removeaxis(AxisX)