Qt示例解析 【图表应用二】Axis

目的：介绍Qt图表中一些特殊的轴，如时间轴DateTimeAxis，对数轴LogValue

示例一【时间轴DateTimeAxis】

QDateTimeAxis *axisX = new QDateTimeAxis;
axisX->setTickCount(10);
axisX->setFormat("MMM yyyy");
axisX->setTitleText("Date");
chart->addAxis(axisX, Qt::AlignBottom);
series->attachAxis(axisX);

示例二【对数轴LogValueAxis】

    QLogValueAxis *axisY = new QLogValueAxis();
    axisY->setTitleText("Values");
    axisY->setLab