How to modify the color and width of a specific grid line in QChartView

[a364858]

I want to highlight the only one grid line.

I tried to subclass QChartView and reimplemented paintEvent(). And then I drew a line in the same place as the gird line.

But it covers the points on QScatterSeries.

What i expect is that the points on QScatterSeries covers the new line, or the color and width of a specific grid line can be modified directly.

[a364858]

Drawing a QGraphicsRectItem to cover the grid line is the solution.

QChart * pChart = new QChart(nullptr);
// add axises, series, points
QGraphicsRectItem * pItem = new QGraphicsRectItem(0, 0, 0, 0, pChart->graphicsItem());
pItem->setPen(QPen(Qt::red));
pItem->setBrush(QPen(Qt::red));
pItem->setZValue(3); // points on QScatterSeries covers  this item and this item covers grid lines
pItem->setRect(/*   */); // to cover the gird line