Qt绘制Wifi图标

效果图

#头文件

#ifndef WIFIICON_H
#define WIFIICON_H

#include <QWidget>

class QTimer;
class WifiIcon : public QWidget
{
    Q_OBJECT
public:
    explicit WifiIcon(QWidget *parent = nullptr);

signals:

public:
    /**
     * 参数二：半径
     * 参数三：开始的角度
     * 参数四：指扫取的角度-顺时针（360度 / 8 = 45度）
     * 参数五：圆环的高度
     * 参数六：填充色
    **/
    void drawCircularArc(QPainter *painter, int radius, int startAngle, int angleLength, int arcHeight);
    double getMinValue()            const;
    double getMaxValue()            const;
    void reStart(bool IsOpen);
public slots:
    //设置最大最小值
    void setMinValue(double minValue);
    void setMaxValue(double maxValue);
    void setCurrentValue(double currentValue);
    void slots_TimeOut();
protected:
    void paintEvent(QPaintEvent *);

protected:
    double m_MinValue;
    double m_MaxValue;
    double m_CurrentValue;

    bool IsReStart;
    QTimer *m_Timer;
};

#endif // WIFIICON_H

#C文件

#include "wifiicon.h"
#include "qpainter.h"
#include "qtimer.h"
#include "qdebug.h"
#include <QTimer>
WifiIcon::WifiIcon(QWidget *parent) : QWidget(parent)
{
    IsReStart=false;
    m_CurrentValue=100;
    m_MinValue=0;
    m_MaxValue=100;
    m_Timer=new QTimer(this);
    connect(m_Timer,&QTimer::timeout,this,&WifiIcon::slots_TimeOut);
}

void WifiIcon::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
    painter.setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing);

    double Width = width();
    double Height = height();
    painter.setPen(Qt::SolidLine);
    int minWidHei;
    if(Height>Width){
        minWidHei=Width;
    }else{
        minWidHei=Height;
    }
    double radius_1=minWidHei/9.5;
    double radius_2 = Height*0.85;
    int arcHeight = Height/10.5;

    QColor Color_1(255, 255, 255);
    QColor Color_2(100,100,100);


    int splitValue=0;
    if(m_CurrentValue<50)
    {
        splitValue=3;
    }else if(m_CurrentValue>=50&&m_CurrentValue<60)
    {
        splitValue=2;
    }else if(m_CurrentValue>=60&&m_CurrentValue<70)
    {
        splitValue=1;
    }else if(m_CurrentValue>=70&&m_CurrentValue<80)
    {
        splitValue=0;
    }else if(m_CurrentValue>=80)
    {
        splitValue=-1;
    }
    for(int i=0;i<4;i++){
        if(i<=splitValue&&splitValue!=-1){
            painter.setBrush(Color_1);
            painter.setPen(Color_1);
        }else{
            painter.setBrush(Color_2);
            painter.setPen(Color_2);
        }
        switch (i) {
        case 0:
            painter.drawEllipse(QPointF(Width*0.5,Height*0.88),radius_1,radius_1);
            painter.translate(QPointF(Width*0.5,Height*0.9));//使用QPainter::translate()函数平移坐标系统；实际就是重新设置坐标原点
            break;
        case 1:
            drawCircularArc(&painter, radius_2*0.40,45,90, arcHeight);
            break;
        case 2:
            drawCircularArc(&painter, radius_2*0.70,45,90, arcHeight);
            break;
        case 3:
            drawCircularArc(&painter, radius_2, 45,90, arcHeight);
            break;
        }
    }
}
void WifiIcon::drawCircularArc(QPainter *painter, int radius, int startAngle, int angleLength, int arcHeight)
{
    QRectF rect(-radius, -radius, radius<<1, radius<<1);
    QPainterPath path;
    path.arcTo(rect, startAngle, angleLength);

    QPainterPath subPath;
    subPath.addEllipse(rect.adjusted(arcHeight, arcHeight, -arcHeight, -arcHeight));
    // path为扇形 subPath为椭圆
    path -= subPath;
    painter->drawPath(path);
//    painter->setBrush(Qt::NoBrush);
//    painter->drawRect(rect);
//    painter->drawRect(rect.adjusted(arcHeight, arcHeight, -arcHeight, -arcHeight));
}

double WifiIcon::getMinValue() const
{
    return m_MinValue;
}

double WifiIcon::getMaxValue() const
{
    return m_MaxValue;
}

void WifiIcon::reStart(bool IsOpen)
{
    if(IsReStart==IsOpen){ return; }
    if(IsOpen==true){
        m_Timer->start(200);
        IsReStart=true;
    }else{
        m_Timer->stop();
        IsReStart=false;
        setCurrentValue(100);
    }
}

void WifiIcon::setMinValue(double minValue)
{
    m_MinValue=minValue;
    update();
}

void WifiIcon::setMaxValue(double maxValue)
{
    m_MaxValue=maxValue;
    update();
}

void WifiIcon::setCurrentValue(double currentValue)
{
    if(IsReStart==true){
        IsReStart=false;
        m_Timer->stop();
    }

    if(currentValue<0){ currentValue=currentValue*-1; }
    m_CurrentValue=currentValue;
    update();
}

void WifiIcon::slots_TimeOut()
{
    m_CurrentValue-=5;
    if(m_CurrentValue<=45){
        m_CurrentValue=86;
    }
    update();
}

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