效果图

基于QPropertyAnimation实现

代码部分

//设置滑动条动画
m_scrollAnimation=new QPropertyAnimation;
m_scrollAnimation->setTargetObject(this);
m_scrollAnimation->setPropertyName("value");
m_scrollAnimation->setEasingCurve(QEasingCurve::OutQuint);
m_scrollAnimation->setDuration(1000);
m_targetValue =value();

void SmoothScrollBar::setValue(int value)
{
    m_scrollAnimation->stop();
    m_scrollAnimation->setStartValue(this->value());
    m_scrollAnimation->setEndValue(value);
    m_scrollAnimation->start();
}

void SmoothScrollBar::scroll(int value)
{
	m_targetValue -= value;
    setValue(m_targetValue);
}

void SmoothScrollBar::mousePressEvent(QMouseEvent *e)
{
    m_scrollAnimation->stop();
    QScrollBar::mousePressEvent(e);
	m_targetValue = value();

}

void SmoothScrollBar::mouseReleaseEvent(QMouseEvent *e)
{
    m_scrollAnimation->stop();
    QScrollBar::mouseReleaseEvent(e);
	m_targetValue = value();
}

void SmoothScrollBar::mouseMoveEvent(QMouseEvent *e)
{
    m_scrollAnimation->stop();
    QScrollBar::mouseMoveEvent(e);
	m_targetValue = value();
}

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