graphicsview框架的交互式K线，给出详细的C/C++代码

以下是一个基于GraphicsView框架实现的交互式K线的C++代码示例：

#include <QtWidgets>
#include <cmath>

class KLineChart : public QGraphicsView
{
    Q_OBJECT

public:
    KLineChart(QWidget *parent = nullptr)
        : QGraphicsView(parent)
    {
        // 设置场景大小
        scene = new QGraphicsScene(this);
        scene->setSceneRect(0, 0, 800, 600);
        setScene(scene);

        // 初始化数据
        const int dataCount = 100;
        for (int i = 0; i < dataCount; ++i) {
            qreal x = i * 8;
            qreal y = 200 + std::sin(i * M_PI / 10.0) * 100;
            data.append(QPointF(x, y));
        }

        // 绘制K线
        drawKLine();

        // 启用交互模式
        setInteractive(true);
        setDragMode(QGraphicsView::ScrollHandDrag);
    }

protected:
    void wheelEvent(QWheelEvent *event) override
    {
        // 缩放场景
        if (event->modifiers() == Qt::ControlModifier) {
            int delta = event->angleDelta().y();
            if (delta > 0)
                scale(1.2, 1.2);
            else if (delta < 0)
                scale(1.0 / 1.2, 1.0 / 1.2);
            event->accept();
        } else {
            QGraphicsView::wheelEvent(event);
        }
    }

    void mousePressEvent(QMouseEvent *event) override
    {
        // 记录初始点
        if (event->button() == Qt::LeftButton) {
            lastPos = event->pos();
            event->accept();
        } else {
            QGraphicsView::mousePressEvent(event);
        }
    }

    void mouseMoveEvent(QMouseEvent *event) override
    {
        // 拖动场景
        if (event->buttons() & Qt::LeftButton) {
            QPointF delta = mapToScene(lastPos) - mapToScene(event->pos());
            translate(delta.x(), delta.y());
            lastPos = event->pos();
            event->accept();
        } else {
            QGraphicsView::mouseMoveEvent(event);
        }
    }

private:
    void drawKLine()
    {
        // 计算K线和坐标轴的位置和大小
        qreal klineX = 50;
        qreal klineY = 50;
        qreal klineWidth = scene->width() - 2 * klineX;
        qreal klineHeight = scene->height() - 2 * klineY;
        qreal xAxisY = klineY + klineHeight * 0.8;
        qreal yAxisX = klineX + klineWidth * 0.1;
        qreal yAxisWidth = klineWidth * 0.1;

        // 绘制坐标轴
        QPen axisPen(Qt::gray, 1);
        scene->addLine(yAxisX, klineY, yAxisX, xAxisY, axisPen);
        scene->addLine(yAxisX + yAxisWidth, klineY, yAxisX + yAxisWidth, xAxisY, axisPen);
        scene->addLine(yAxisX, xAxisY, yAxisX + yAxisWidth, xAxisY, axisPen);

        // 绘制K线
        qreal klineItemWidth = klineWidth / data.count();
        QPen klinePen(Qt::black, 1);
        for (int i = 0; i < data.count(); ++i) {
            QPointF point = data.at(i);
            qreal x = klineX + i * klineItemWidth;
            qreal y = xAxisY - (point.y() - 200) / 100.0 * klineHeight * 0.6;
            qreal height = std::abs(point.y() - 200) / 100.0 * klineHeight * 0.6;
            QRectF rect(x, y, klineItemWidth, height);
            QGraphicsRectItem *item = scene->addRect(rect, klinePen);
            if (point.y() > 200) {
                item->setBrush(Qt::red);
            } else {
                item->setBrush(Qt::green);
            }
        }
    }

private:
    QGraphicsScene *scene;
    QList<QPointF> data;
    QPoint lastPos;
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    KLineChart chart;
    chart.show();

    return app.exec();
}

#include "main.moc"

这个示例实现了一个简单的K线图，通过鼠标拖动和滚轮缩放实现了交互。你可以根据你的需求修改和扩展这个示例。