前文链接：QGraphicsView实现简易地图16『爆炸效果』
模仿水波荡漾时的涟漪效果，参考了echarts中的散点图
支持设置散点大小、颜色、涟漪线条宽度。
动态演示效果

静态展示图片

核心代码

#pragma once
#include "../AbstractGeoItem.h"
#include "DataStruct/GeoData.h"/** 散点效果-静态*/class EffectScatterItem : public AbstractGeoItem
{
public:explicit EffectScatterItem(const GeoCoord &geoCoord, int radius, QGraphicsItem *parent = nullptr);~EffectScatterItem();// 设置百分比（值：0-1）void setPercent(double percent);// 获取百分比double percent();// 设置颜色void setColor(QColor color);// 设置涟漪线宽void setRippleWidth(double width);protected:virtual QRectF boundingRect() const override;virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;private:int m_radius;			// 半径（单位：像素）double m_percent;		// 每条涟漪扩散百分比double m_ripplesWidth;	// 涟漪线宽QColor m_color;			// 颜色
};

#include "EffectScatterItem.h"
#include <QPainter>EffectScatterItem::EffectScatterItem(const GeoCoord &geoCoord, int radius, QGraphicsItem *parent /*= nullptr*/): AbstractGeoItem(parent)
{setZValue(302);setGeoPos(geoCoord.lon, geoCoord.lat);m_radius = radius;m_percent = 0;m_ripplesWidth = 1.5;m_color = Qt::white;
}EffectScatterItem::~EffectScatterItem()
{}void EffectScatterItem::setPercent(double percent)
{m_percent = percent;update();
}double EffectScatterItem::percent()
{return m_percent;
}void EffectScatterItem::setColor(QColor color)
{m_color = color;update();
}void EffectScatterItem::setRippleWidth(double width)
{m_ripplesWidth = width;update();
}QRectF EffectScatterItem::boundingRect() const
{return QRectF(-m_radius, -m_radius, 2 * m_radius, 2 * m_radius);
}void EffectScatterItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{painter->setPen(Qt::NoPen);painter->setBrush(m_color);painter->setRenderHint(QPainter::Antialiasing);painter->drawEllipse(QPointF(0, 0), m_radius * 0.4, m_radius * 0.4);painter->setBrush(Qt::NoBrush);for (int i = 1; i <= 3; ++i){QColor color = m_color;color.setAlphaF((4 - i - m_percent) / 3);painter->setPen(QPen(color, m_ripplesWidth));double radius = m_radius * (0.4 + (i - 1 + m_percent) * 0.2);painter->drawEllipse(QPointF(0, 0), radius, radius);}
}