Qt 圆形进度条实现

分手后的思念是犯贱 2023-06-08 09:25 31阅读 0赞

# 1.运行截图 #

![20191017181959480.gif][]![20191017182024918.gif][]![20191017182041705.gif][]

# 2.源码 #

.h
    
    #ifndef _QROUNDPROGRESSBAR_H_
    #define _QROUNDPROGRESSBAR_H_
    
    #include <QWidget>
    
    class QRoundProgressBar : public QWidget
    {
        Q_OBJECT
    
        //进度条形状
        enum BarStyle
        {
            //圆环状
            StyleDonut = 0,
            //圆饼状
            StylePie,
            //圆线状
            StyleLine
        };
    
    
    public:
        QRoundProgressBar(QWidget *parent , BarStyle style = StyleLine);
        ~QRoundProgressBar();
    
    public:
        //设置扫描弧度起始角度
        void setStartAngle(double position);
    
        //设置轮廓画笔的宽度
        void setOutlinePenWidth(double penWidth);
    
        //设置画笔宽度
        void setDataPenWidth(double penWidth);
    
        //设置进度条精度 88.88%,几位小数
        void setDecimals(int count);
    
        //设置进度条风格
        void setBarStyle(BarStyle style);
    
        //设置范围
        void setRange(double min, double max);
    
        //设置当前值
        void setValue(int val);
    
        //设置当前值
        void setValue(double val);
    
        //设置最小值
        void setMinimum(double min);
    
        //设置最大值
        void setMaximum(double max);
    
    protected:
        void paintEvent(QPaintEvent *event);
    
        //画基础图形
        void drawBase(QPainter& p, const QRectF& baseRect, const QRectF &innerRect);
    
        //根据值画出进度条
        void drawValue(QPainter& p, const QRectF& baseRect, double value, double arcLength, const QRectF & innerRect
            , double innerDiameter);
    
        //画中心文字
        void drawText(QPainter& p, const QRectF& innerRect, double value);
    
    private:
        double   m_min;                                 //最小值
        double   m_max;                                 //最大值
        double   m_value;                               //当前值
        BarStyle m_barStyle;                            //进度条风格
        int      m_decimals;                            //进度条精度
        double   m_startAngel;                          //扫描弧度起始角度
        double   m_outlinePenWidth;                     //轮廓画笔的宽度
        double   m_dataPenWidth;                        //画笔宽度
    };
    
    #endif // _QROUNDPROGRESSBAR_H_

.cpp
    #include "QRoundProgressBar.h"
    #include <QPainter>
    #include <QPointF>
    #include <QtMath>
    
    QRoundProgressBar::QRoundProgressBar(QWidget *parent , BarStyle style)
        : QWidget(parent)
        , m_min(0)
        , m_max(100)
        , m_value(0)
        , m_startAngel(90)
        , m_barStyle(style)
        , m_outlinePenWidth(0)
        , m_dataPenWidth(0)
        , m_decimals(0)
    {
    }
    
    QRoundProgressBar::~QRoundProgressBar()
    {
    }
    
    
    void QRoundProgressBar::setStartAngle(double angle)
    {
        if (angle != m_startAngel)
        {
            m_startAngel = angle;
            update();
        }
    }
    
    void QRoundProgressBar::setOutlinePenWidth(double penWidth)
    {
        if (penWidth != m_outlinePenWidth)
        {
            m_outlinePenWidth = penWidth;
            update();
        }
    }
    
    
    void QRoundProgressBar::setDataPenWidth(double penWidth)
    {
        if (penWidth != m_dataPenWidth)
        {
            m_dataPenWidth = penWidth;
            update();
        }
    }
    
    
    
    void QRoundProgressBar::setDecimals(int count)
    {
        if (count >= 0 && count != m_decimals)
        {
            m_decimals = count;
            update();
        }
    }
    
    
    void QRoundProgressBar::setBarStyle(BarStyle style)
    {
        if (style != m_barStyle)
        {
            m_barStyle = style;
            update();
        }
    }
    
    
    void QRoundProgressBar::setRange(double min, double max)
    {
        m_min = min;
        m_max = max;
    
        if (m_max < m_min)
        {
            qSwap(m_max, m_min);
        }
    
        if (m_value < m_min)
        {
            m_value = m_min;
        }
        else if (m_value > m_max)
        {
            m_value = m_max;
        }
    
        update();
    }
    
    void QRoundProgressBar::setValue(double val)
    {
        if (m_value != val)
        {
            if (val < m_min)
            {
                m_value = m_min;
            }
            else if (val > m_max)
            {
                m_value = m_max;
            }
            else
            {
                m_value = val;
            }
            update();
        }
    }
    
    void QRoundProgressBar::setValue(int val)
    {
        setValue(double(val));
    }
    
    
    void QRoundProgressBar::setMinimum(double min)
    {
        setRange(min, m_max);
    }
    
    void QRoundProgressBar::setMaximum(double max)
    {
        setRange(m_min, max);
    }
    
    
    void QRoundProgressBar::paintEvent(QPaintEvent* /*event*/)
    {
        //外圈直径
        double outerDiameter = this->width();
    
        //外圈矩形
        QRectF baseRect(0, 0, outerDiameter, outerDiameter);
    
        QPainter p(this);
        p.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
    
        //画背景矩形填充白色
        p.fillRect(baseRect, QBrush(QColor("#FFFFFF")));
    
        //内圆直径
        double innerDiameter;
    
        //内圈矩形
        QRectF innerRect;
    
        //计算内圈矩形
        if (m_barStyle == StyleLine)
        {
            innerDiameter = outerDiameter - m_outlinePenWidth;
        }
    
        else if(m_barStyle == StyleDonut)
        {
            innerDiameter = outerDiameter * 0.9;
        }
    
        double delta = (outerDiameter - innerDiameter) / 2;
    
        innerRect = QRectF(delta, delta, innerDiameter, innerDiameter);
    
    
        //画基础图形
        drawBase(p, baseRect, innerRect);
    
        //计算当前步长比例
        double arcStep = 360.0 / (m_max - m_min) * m_value;
    
        //根据值画出进度条
        drawValue(p, baseRect, m_value, arcStep, innerRect, innerDiameter);
    
        //画文字
        drawText(p, baseRect, m_value);
    
        p.end();
    }
    
    void QRoundProgressBar::drawBase(QPainter &p, const QRectF &baseRect, const QRectF &innerRect)
    {
        switch (m_barStyle)
        {
            case StyleDonut:
            {
                QPainterPath dataPath;
                dataPath.setFillRule(Qt::OddEvenFill);
                dataPath.moveTo(baseRect.center());
                dataPath.addEllipse(innerRect);
    
                QPen pen;
                pen.setColor(QColor("#DEE3E7"));
                pen.setWidth(10);
                p.setPen(pen);
                p.setBrush(QBrush(QColor("#FFFFFF")));
            
                p.drawPath(dataPath);
                break;
            }
    
            case StylePie:
            {
                p.setPen(QPen(QColor("#FFFFFF"), m_outlinePenWidth));
                p.setBrush(QBrush(QColor("#DEE3E7")));
                p.drawEllipse(baseRect);
                break;
            }
    
            case StyleLine:
            {
                p.setPen(QPen(QColor("#FFFFFF"), m_outlinePenWidth));
                p.setBrush(Qt::NoBrush);
                p.drawEllipse(baseRect.adjusted(m_outlinePenWidth / 2, m_outlinePenWidth / 2, -m_outlinePenWidth / 2, -m_outlinePenWidth / 2));
                break;
            }
    
            default:
            {
                break;
            }
        }
    }
    
    void QRoundProgressBar::drawValue(QPainter &p, const QRectF &baseRect , double value, double arcLength
                              , const QRectF & innerRect, double innerDiameter)
    {
        if (value == m_min)
        {
            return;
        }
    
        if (m_barStyle == StyleLine)
        {
            p.setPen(QColor("#2F8DED"));
            p.setBrush(Qt::NoBrush);
            p.drawArc(baseRect,m_startAngel * 16, -arcLength * 16);
        }
        else if (m_barStyle == StyleDonut)
        {
            QPen pen;
            pen.setColor(QColor("#2F8DED"));
            pen.setWidth(10);
            pen.setCapStyle(Qt::RoundCap);
            p.setPen(pen);
            p.drawArc(innerRect, m_startAngel*16 , -16*arcLength);
        }
        else
        {
            //获取中心点坐标
            QPointF centerPoint = baseRect.center();
            QPainterPath dataPath;
            dataPath.setFillRule(Qt::WindingFill);
            dataPath.moveTo(centerPoint);
            //逆时针画弧长
            dataPath.arcTo(baseRect, m_startAngel, -arcLength);
            if (m_barStyle == StylePie)
            {
                dataPath.lineTo(centerPoint);
                p.setPen(QPen(QColor("#2F8DED"), m_dataPenWidth));
            }
            p.setBrush(QBrush(QColor("#2F8DED")));
            p.drawPath(dataPath);
        }
    
    }
    
    void QRoundProgressBar::drawText(QPainter &p, const QRectF &rect, double value)
    {
        QString textToDraw = "%";
        double percent = (value - m_min) / (m_max - m_min) * 100.0;
        textToDraw = QString::number(percent, 'f', m_decimals) + textToDraw;
    
        QFont f;
        f.setFamily("微软雅黑");
        f.setPixelSize(20);
    
        p.setFont(f);
        p.setPen(QColor("#606266"));
    
        p.drawText(rect, Qt::AlignCenter, textToDraw);
    }

[20191017181959480.gif]: https://img-blog.csdnimg.cn/20191017181959480.gif
[20191017182024918.gif]: https://img-blog.csdnimg.cn/20191017182024918.gif
[20191017182041705.gif]: /images/20230531/6e5947723b584c07b734e29abe69df89.png