QT 实现曲线的动态绘制 完整类

以下是一个基于QT的曲线动态绘制的完整类，包含了一些常用的曲线绘制函数和动画效果。

#include <QWidget>
#include <QTimer>
#include <QPainter>
#include <QVector>

class CurveWidget : public QWidget
{
    Q_OBJECT

public:
    CurveWidget(QWidget *parent = 0);
    ~CurveWidget();

    void setCurveData(const QVector<QPointF> &data);

public slots:
    void startAnimation();

protected:
    void paintEvent(QPaintEvent *event);

private:
    QVector<QPointF> m_curveData;
    QTimer *m_timer;
    int m_offset;
};

CurveWidget::CurveWidget(QWidget *parent)
    : QWidget(parent)
{
    m_timer = new QTimer(this);
    m_offset = 0;
    connect(m_timer, SIGNAL(timeout()), this, SLOT(update()));
}

CurveWidget::~CurveWidget()
{
}

void CurveWidget::setCurveData(const QVector<QPointF> &data)
{
    m_curveData = data;
    update();
}

void CurveWidget::startAnimation()
{
    m_timer->start(50);
}

void CurveWidget::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);

    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);

    // 绘制坐标系
    painter.drawLine(20, height() - 20, width() - 20, height() - 20);
    painter.drawLine(20, 20, 20, height() - 20);

    // 绘制曲线
    QPolygonF polygon;
    for (int i = 0; i < m_curveData.size(); ++i) {
        QPointF point(m_curveData.at(i).x() + m_offset, m_curveData.at(i).y());
        if (i == 0) {
            polygon << QPointF(20, height() - 20);
            polygon << point;
        } else {
            QPointF p1 = polygon.at(i);
            QPointF p2 = point;
            QPointF c1((p1.x() + p2.x()) / 2, p1.y());
            QPointF c2(c1.x(), p2.y());
            polygon << c1 << c2 << p2;
        }
    }
    if (polygon.size() > 1) {
        painter.drawPolyline(polygon);
    }

    // 更新偏移量
    m_offset += 1;
    if (m_offset > width() - 40) {
        m_offset = 0;
    }
}

使用方法：

1. 创建一个 CurveWidget 对象，并将其添加到窗口中。
2. 调用 setCurveData 函数设置曲线数据。
3. 调用 startAnimation 函数启动动画效果。

示例：

QVector<QPointF> data;
data << QPointF(0, 100) << QPointF(50, 200) << QPointF(100, 150)
     << QPointF(150, 250) << QPointF(200, 200) << QPointF(250, 300)
     << QPointF(300, 250) << QPointF(350, 350) << QPointF(400, 300);
CurveWidget *curveWidget = new CurveWidget(this);
curveWidget->setCurveData(data);
curveWidget->startAnimation();