Qt画波浪球（小费力）

 画流动波浪

#ifndef WIDGET3_H
#define WIDGET3_H#include <QWidget>
#include <QtMath>
class widget3 : public QWidget
{Q_OBJECT
public:explicit widget3(QWidget *parent = nullptr);void set_value(int v){value=v;}int get_value(){return value;}
protected:void paintEvent(QPaintEvent *event) override;void timerEvent(QTimerEvent *event) override;
signals:private:double m_water_H=0.2;//振幅系数double m_offset=0;//偏移量int m_updateTime =100;//移动速度int value;
};#endif // WIDGET3_H

#include "widget3.h"
#include <QPainter>
#include <QDebug>
widget3::widget3(QWidget *parent) : QWidget(parent)
{m_updateTime=100;value=30;this->startTimer(m_updateTime);
}void widget3::paintEvent(QPaintEvent *event)
{QPainter painter(this);painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::TextAntialiasing, true);//y = A * qSin(ωx + φ) + k//0或100时会有bugdouble h1=height()*(1-(1.0*value/100));//波线的中间点painter.translate(0,h1);m_water_H=0.05;double A=height()*m_water_H;//振幅double T=width()/2;double w=2*M_PI/T;//W=2pi/T,T越大，w越小double k=0;QPainterPath waterPath;double h2=height()-h1;waterPath.moveTo(0,h2);waterPath.lineTo(0,0);if(m_offset == T){m_offset=0;}else{m_offset+=T/10;}for(int x=0;x<=width();x++){double waterY=-(double)(A*sin(w*x+m_offset))+k;waterPath.lineTo(x,waterY);}waterPath.lineTo(width(),h2);painter.setPen(Qt::NoPen);painter.setBrush(QBrush(QColor(166, 196, 255)));painter.drawPath(waterPath);
}void widget3::timerEvent(QTimerEvent *event)
{this->update();
}

 QRadialGradient简单使用

void widget2::paintEvent(QPaintEvent *event)
{QPainter painter(this);painter.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform | QPainter::TextAntialiasing, true);double side=fmin(width(),height());QRadialGradient radialGradient(width()/2, height()/2, side, width()/2, height()/2);radialGradient.setColorAt(0,Qt::red);radialGradient.setColorAt(0.5,Qt::blue);        //设置50%处的半径为蓝色radialGradient.setColorAt(1,Qt::green);painter.setBrush(radialGradient);painter.drawEllipse((width()-side) / 2, 0, side, side);
}

 为球中流动波浪添加渐变效果

    QRadialGradient radialGradient(width()/2,height()/2,side/2,width()/2,height()/2);radialGradient.setColorAt(1,QColor(102, 145, 255));radialGradient.setColorAt(0.90,QColor(157, 190, 255));radialGradient.setColorAt(0,QColor(157, 190, 255));painter.setBrush(radialGradient);painter.drawPath(path);

 为外层再套上一层渐变效果

void widget3::draw_Circle(QPainter &painter)
{painter.save();//y = A * qSin(ωx + φ) + k//0或100时会有bugqDebug()<<value;double h1=height()*(1-(1.0*value/100));//波线的中间点，value=30，高度为0.7*height()m_water_H=0.05;double A=height()*m_water_H;//振幅double T=width()/2;double w=2*M_PI/T;//W=2pi/T,T越大，w越小double k=0;QPainterPath waterPath;double h2=height()-h1;//这里就是0.3*height()waterPath.moveTo(0,height());waterPath.lineTo(0,h2);if(m_offset == T){m_offset=0;}else{m_offset+=T/10;}for(int x=0;x<=width();x++){double waterY=-(double)(A*sin(w*x+m_offset))+k;waterPath.lineTo(x,waterY+h1);}waterPath.lineTo(width(),height());QPainterPath bigPath;double side=fmin(width(),height());painter.setPen(Qt::NoPen);painter.setBrush(QBrush(QColor(255,255,255)));painter.drawEllipse(width()/2-side*0.45,height()/2-side*0.45,side*0.9,side*0.9);bigPath.addEllipse(width()/2-side*0.45,height()/2-side*0.45,side*0.9,side*0.9);//新路径,用大路径减去波浪区域的路径,形成遮罩效果QPainterPath path;//圆的部分与波浪的部分结合path = bigPath.intersected(waterPath);painter.setPen(Qt::NoPen);//r=0.5side,r1=0.45side//r1*0.9=0.45side*0.9=0.5side*0.81QRadialGradient radialGradient1(width()/2,height()/2,side/2,width()/2,height()/2);radialGradient1.setColorAt(1,QColor(235, 243, 255));radialGradient1.setColorAt(0.81,QColor(255,255,255));radialGradient1.setColorAt(0,QColor(255,255,255));painter.setBrush(radialGradient1);painter.drawEllipse(width()/2-side/2,height()/2-side/2,side,side);QRadialGradient radialGradient(width()/2,height()/2,side*0.45,width()/2,height()/2);radialGradient.setColorAt(1,QColor(102, 145, 255));radialGradient.setColorAt(0.90,QColor(157, 190, 255));radialGradient.setColorAt(0,QColor(157, 190, 255));painter.setBrush(radialGradient);painter.drawPath(path);painter.restore();
}

 画文字

void widget3::drawText1(QPainter &painter,QString text)
{painter.save();double x_center,y_center;x_center=width()/2;y_center=height()/2;painter.translate(x_center,y_center);QFont font;font.setPointSize(15);font.setFamily("方正粗黑宋简体");painter.setFont(font);QPen pen;pen.setColor(QColor(0,0,0));painter.setPen(pen);painter.drawText(-100,-50,200,50,Qt::AlignCenter,text);painter.restore();
}void widget3::drawText2(QPainter &painter, QString text)
{painter.save();double x_center,y_center;x_center=width()/2;y_center=height()/2;painter.translate(x_center,y_center);QFont font;font.setPointSize(10);painter.setFont(font);QPen pen;pen.setColor(QColor(97, 99, 102));painter.setPen(pen);painter.drawText(-100,0,200,50,Qt::AlignCenter,text);painter.restore();
}

注释：一些细节需要自己去调整参数