QT实现wifi信号强弱图标

        Qt界面中绘制WiFi信号强弱图标。模拟类似手机的WIFI强度图标的绘制，比较简单，欢迎参考。

一、简述

        使用Qt实现WIFI信号图标。

二、效果 

三、核心代码  

 1、头文件

#ifndef WIFIICON_H
#define WIFIICON_H

#include <QWidget>

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

    //信号强度
    enum wifiStrength{
        Zero = 0,
        One,
        Two,
        Three,
        Four
    };

    //设置信号强度
    void setStrength(wifiStrength strength);

protected:
    void paintEvent(QPaintEvent *);
    void drawCircularArc(QPainter *painter, int radius, int startAngle, int angleLength, int arcHeight);

private:
    wifiStrength m_wifiStrength;
};

#endif // WIFIICON_H

2、cpp代码 

#include "wifiicon.h"
#include <QPainter>
#include <QTimer>

WifiIcon::WifiIcon(QWidget *parent) : QWidget(parent)
{
    m_wifiStrength = wifiStrength::Zero;
}

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 havaSignal = Qt::white;
    QColor noSignal = QColor(100,100,100);
    int splitValue=0;
    switch(m_wifiStrength)
    {
    case WifiIcon::Four:
        splitValue=4;
        break;
    case WifiIcon::Three:
        splitValue=3;
        break;
    case WifiIcon::Two:
        splitValue=2;
        break;
    case WifiIcon::One:
        splitValue=1;
        break;
    default:
        break;
    };

    for(int i=1;i<5;i++){
        if(i<=splitValue&&splitValue!=0){
            painter.setBrush(havaSignal);
            painter.setPen(havaSignal);
        }else{
            painter.setBrush(noSignal);
            painter.setPen(noSignal);
        }
        switch (i) {
        case 1:
            painter.drawEllipse(QPointF(Width*0.5,Height*0.88),radius_1,radius_1);
            painter.translate(QPointF(Width*0.5,Height*0.9));
            break;
        case 2:
            drawCircularArc(&painter, radius_2*0.40,45,90, arcHeight);
            break;
        case 3:
            drawCircularArc(&painter, radius_2*0.70,45,90, arcHeight);
            break;
        case 4:
            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 -= subPath;
    painter->drawPath(path);
}

void WifiIcon::setStrength(wifiStrength strength)
{
    m_wifiStrength = strength;
    update();
}

3、示例下载