QChart柱状图、折线图和散点图添加标注提示框

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因为比较简单所以直接上代码

mainwindow.cpp

m_tooltip(0)//初始化

void MainWindow::initChart()

{

/****

to do

****/

    m_barSeries = new QBarSeries(m_typeChart);

    connect(m_barSeries, SIGNAL(hovered(bool, int, QBarSet*)), this, SLOT(sltTooltip(bool, int, QBarSet*)));

//    QLineSeries *series = new QLineSeries（m_typeChart）;

//    connect(series, SIGNAL(hovered(QPointF, bool)), this, SLOT(sltTooltip(QPointF,bool)));//折线图

/****

to do

****/

}

void MainWindow::addBarSet()

{

    *m_barSet << 1 << 2 << 3 << 4 << 5 << 6;

    m_barSeries->append(m_barSet);

    m_categories  << "Feb" << "Mar" << "Apr" << "May" << "Jun" << "Jan";

    m_typeAxis->append(m_categories);//

}

void MainWindow::sltTooltip(bool status, int index, QBarSet *barset)

{

    if (m_tooltip == 0)

        m_tooltip = new ChartTip(m_typeChart);

    if (status) {

        m_tooltip->setText("X: "+m_categories.at(index)+"\n"+QString("Y: %2 ").arg(barset->at(index)));

        QPointF point(index, barset->at(index));

        m_tooltip->setAnchor(point);

        m_tooltip->setZValue(11);

        m_tooltip->updateGeometry();

        m_tooltip->show();

    }

    else {

        m_tooltip->hide();

    }

}

charttip.cpp

QRectF ChartTip::boundingRect() const

{

    QPointF anchor = mapFromParent(m_chart->mapToPosition(m_anchor));

    QRectF rect;

    rect.setLeft(qMin(m_rect.left(), anchor.x()));

    rect.setRight(qMax(m_rect.right(), anchor.x()));

    rect.setTop(qMin(m_rect.top(), anchor.y()));

    rect.setBottom(qMax(m_rect.bottom(), anchor.y()));

    return rect;

}

void ChartTip::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)

{

    Q_UNUSED(option)

    Q_UNUSED(widget)

    QPainterPath path;

    path.addRoundedRect(m_rect, 5, 5);

    QPointF anchor = mapFromParent(m_chart->mapToPosition(m_anchor));

    if (!m_rect.contains(anchor)) {

        QPointF point1, point2;

        // establish the position of the anchor point in relation to m_rect

        bool above = anchor.y() <= m_rect.top();

        bool aboveCenter = anchor.y() > m_rect.top() && anchor.y() <= m_rect.center().y();

        bool belowCenter = anchor.y() > m_rect.center().y() && anchor.y() <= m_rect.bottom();

        bool below = anchor.y() > m_rect.bottom();

        bool onLeft = anchor.x() <= m_rect.left();

        bool leftOfCenter = anchor.x() > m_rect.left() && anchor.x() <= m_rect.center().x();

        bool rightOfCenter = anchor.x() > m_rect.center().x() && anchor.x() <= m_rect.right();

        bool onRight = anchor.x() > m_rect.right();

        // get the nearest m_rect corner.

        qreal x = (onRight + rightOfCenter) * m_rect.width();

        qreal y = (below + belowCenter) * m_rect.height();

        bool cornerCase = (above && onLeft) || (above && onRight) || (below && onLeft) || (below && onRight);

        bool vertical = qAbs(anchor.x() - x) > qAbs(anchor.y() - y);

        qreal x1 = x + leftOfCenter * 10 - rightOfCenter * 20 + cornerCase * !vertical * (onLeft * 10 - onRight * 20);

        qreal y1 = y + aboveCenter * 10 - belowCenter * 20 + cornerCase * vertical * (above * 10 - below * 20);;

        point1.setX(x1);

        point1.setY(y1);

        qreal x2 = x + leftOfCenter * 20 - rightOfCenter * 10 + cornerCase * !vertical * (onLeft * 20 - onRight * 10);;

        qreal y2 = y + aboveCenter * 20 - belowCenter * 10 + cornerCase * vertical * (above * 20 - below * 10);;

        point2.setX(x2);

        point2.setY(y2);

        path.moveTo(point1);

        path.lineTo(anchor);

        path.lineTo(point2);

        path = path.simplified();

    }

    painter->setBrush(QColor(255, 255, 255));

    painter->drawPath(path);

    painter->drawText(m_textRect, m_text);

}

void ChartTip::setText(const QString &text)

{

    m_text = text;

    QFontMetrics metrics(m_font);

    m_textRect = metrics.boundingRect(QRect(0, 0, 150, 150), Qt::AlignLeft, m_text);

    m_textRect.translate(5, 5);

    prepareGeometryChange();

    m_rect = m_textRect.adjusted(-5, -5, 5, 5);

}

void ChartTip::setAnchor(QPointF point)

{

    m_anchor = point;

}

void ChartTip::updateGeometry()

{

    prepareGeometryChange();

    setPos(m_chart->mapToPosition(m_anchor) + QPoint(10, -50));//QPoint（10,-50）在现实最右边的内容是会出现遮挡所以我在适应时改为（-60，-50）根据实际需求进行修改

}

下载地址：https://download.csdn.net/download/u010304326/10293028

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