Qtcharts不呈现数据

Question

我正在尝试呈现两个图表，除了Y数据之外，它们基本上是相同的。这是代码

QtCharts::QLineSeries *cpuSeries = new QtCharts::QLineSeries();
        QtCharts::QLineSeries *ramSeries = new QtCharts::QLineSeries();

        QString string;
        while((string = in.readLine()) != nullptr){
            QStringList values = string.split(QLatin1Char(';'));
            QDateTime moment = QDateTime::fromString(values[0], "yyyy:MM:dd:hh:mm:ss");

            cpuSeries -> append(moment.toMSecsSinceEpoch(), values[2].toDouble());
            ramSeries -> append(moment.toMSecsSinceEpoch(), values[3].toDouble());

        }

        fileIO.close();
        QtCharts::QChart *cpuChart = new QtCharts::QChart();
        QtCharts::QChart *ramChart = new QtCharts::QChart();
        cpuChart -> addSeries(cpuSeries);
        ramChart -> addSeries(ramSeries);
        cpuChart -> legend() -> hide();
        ramChart -> legend() -> hide();
        cpuChart -> setTitle("Cpu usage over time");
        ramChart -> setTitle("Ram usage over time");


        QtCharts::QDateTimeAxis *cpuaxisX = new QtCharts::QDateTimeAxis;
        cpuaxisX->setTickCount(10);
        cpuaxisX->setFormat("dd-MM hh:mm");
        cpuaxisX->setTitleText("Date");

        QtCharts::QDateTimeAxis *ramaxisX = new QtCharts::QDateTimeAxis;
        ramaxisX->setTickCount(10);
        ramaxisX->setFormat("dd-MM hh:mm");
        ramaxisX->setTitleText("Date");


        cpuChart -> addAxis(cpuaxisX, Qt::AlignBottom);
        cpuSeries -> attachAxis(cpuaxisX);

        ramChart -> addAxis(ramaxisX, Qt::AlignBottom);
        ramSeries ->attachAxis(ramaxisX);

        QtCharts::QValueAxis *cpuaxisY = new QtCharts::QValueAxis;
        cpuaxisY->setLabelFormat("%f");
        cpuaxisY->setTitleText("Percentage");

        QtCharts::QValueAxis *ramaxisY = new QtCharts::QValueAxis;
        ramaxisY->setLabelFormat("%f");
        ramaxisY->setTitleText("Mb");



        cpuChart->addAxis(cpuaxisY, Qt::AlignLeft);
        cpuSeries->attachAxis(cpuaxisY);
        ramChart->addAxis(ramaxisY, Qt::AlignLeft);
        ramSeries->attachAxis(ramaxisY);


        QtCharts::QChartView *cpuChartView = new QtCharts::QChartView(cpuChart);
        QtCharts::QChartView *ramChartView = new QtCharts::QChartView(ramChart);
        cpuChartView -> setRenderHint(QPainter::Antialiasing);
        ramChartView -> setRenderHint(QPainter::Antialiasing);


        QGridLayout *cpuGrid  = ui -> centralwidget -> findChild<QGridLayout *>("cpuGrid");
        QGridLayout *ramGrid = ui -> centralwidget -> findChild<QGridLayout *>("ramGrid");


        cpuGrid -> addWidget(cpuChartView);
        ramGrid -> addWidget(ramChartView);

正如您所看到的，除了数据和标题之外，这两个图表都是使用完全相同的代码创建的。然而，这就是结果

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我已经打印了values3，它是正确的。此外，如果我将values2数据传递给它，它会工作，并且两个图表看起来完全相同。values3值超过10000，这会是问题所在吗？

Answer 1

我发现了问题，但很奇怪...问题是所有的数据都是完全相同的，显然，如果所有的数据都是相同的，它就不会呈现任何东西……我猜这是因为它将范围计算为0，然后它不能显示任何内容……

编辑:实际上，如果我手动设置图形的范围，它会很好地显示数据。