Qt进度条的实现示例_C语言

/***********************************************************************
  作者：liangtianmanyue(QQ:1660941209) 2021-05-30
  功能：进度控件
  1、可设置值动态变化
  2、可设置警戒值
  3、可设置正常颜色和报警颜色
  4、可设置边框渐变颜色
  5、可设置变化时每次移动的步长
  6、可设置错误时显示错误描述
  7、可设置显示值保留小数的位数
  8、可设置边框圆角角度/背景进度圆角角度/头部圆角角度
  ************************************************************************/
  
  #ifndef PROGRESS_LABEL_H
  #define PROGRESS_LABEL_H
  
  #include 
  #include 
  
  #ifdef Plugin
  #if (QT_VERSION 
  #else
  #include 
  #endif
  
  class QDESIGNER_WIDGET_EXPORT ProgressLabel : public QLabel
  #else
  class ProgressLabel : public QLabel
  #endif
  {
      Q_OBJECT    
      Q_PROPERTY(double minValue READ getMinValue WRITE setMinValue)
      Q_PROPERTY(double maxValue READ getMaxValue WRITE setMaxValue)
      Q_PROPERTY(double value READ getValue WRITE setValue)
      Q_PROPERTY(double alarmValue READ getAlarmValue WRITE setAlarmValue)
  
      Q_PROPERTY(double step READ getStep WRITE setStep)
      Q_PROPERTY(int decimals READ getDecimals WRITE setDecimals)
      Q_PROPERTY(int borderRadius READ getBorderRadius WRITE setBorderRadius)
      Q_PROPERTY(int bgRadius READ getBgRadius WRITE setBgRadius)
      Q_PROPERTY(int headRadius READ getHeadRadius WRITE setHeadRadius)
  
      Q_PROPERTY(QColor borderColorStart READ getBorderColorStart WRITE setBorderColorStart)
      Q_PROPERTY(QColor borderColorEnd READ getBorderColorEnd WRITE setBorderColorEnd)
  
      Q_PROPERTY(QColor alarmColorStart READ getAlarmColorStart WRITE setAlarmColorStart)
      Q_PROPERTY(QColor alarmColorEnd READ getAlarmColorEnd WRITE setAlarmColorEnd)
  
      Q_PROPERTY(QColor normalColorStart READ getNormalColorStart WRITE setNormalColorStart)
      Q_PROPERTY(QColor normalColorEnd READ getNormalColorEnd WRITE setNormalColorEnd)
  
  public:
      explicit ProgressLabel(QWidget *parent = 0);
      ~ProgressLabel();
  
  protected:
      void paintEvent(QPaintEvent *);
      void drawBg(QPainter *painter);
  
  private slots:
      void updateValue();
  
  public:    
      double getMinValue()            const;
      double getMaxValue()            const;
      double getValue()               const;
      double getAlarmValue()          const;
  
      double getStep()                const;
      int getBorderRadius()           const;
      int getBgRadius()               const;
      int getHeadRadius()             const;
  
      QColor getBorderColorStart()    const;
      QColor getBorderColorEnd()      const;
  
      QColor getAlarmColorStart()     const;
      QColor getAlarmColorEnd()       const;
  
      QColor getNormalColorStart()    const;
      QColor getNormalColorEnd()      const;
  
      QSize sizeHint()                const;
      QSize minimumSizeHint()         const;
  
  public Q_SLOTS:
      //设置范围值
      void setRange(double minValue, double maxValue);
      void setRange(int minValue, int maxValue);
  
      //设置最大最小值
      void setMinValue(double minValue);
      void setMaxValue(double maxValue);
  
      //设置显示值
      void setValue(double value);
      void setValue(int value);
  
     //设置警戒值
     void setAlarmValue(double alarmValue);
     void setAlarmValue(int alarmValue);
 
     //设置步长
     void setStep(double step);
     void setStep(int step);
 
     //小数点位数
     int getDecimals();
     void setDecimals(int decimals);
 
     //设置边框圆角角度
     void setBorderRadius(int borderRadius);
     //设置背景圆角角度
     void setBgRadius(int bgRadius);
     //设置头部圆角角度
     void setHeadRadius(int headRadius);
 
     //设置边框渐变颜色
     void setBorderColorStart(const QColor &borderColorStart);
     void setBorderColorEnd(const QColor &borderColorEnd);
 
     //设置报警时的渐变颜色
     void setAlarmColorStart(const QColor &alarmColorStart);
     void setAlarmColorEnd(const QColor &alarmColorEnd);
 
     //设置正常时的渐变颜色
     void setNormalColorStart(const QColor &normalColorStart);
     void setNormalColorEnd(const QColor &normalColorEnd);
     
     //正常、异常显示
     void setNormalState();
     void setErrorText(const QString &text);
 
 Q_SIGNALS:
     void valueChanged(double value);
 
 private:
     bool m_IsError;                 //是否出错
     QString m_ErrorText;            //错误描述
 
     double minValue;                //最小值
     double maxValue;                //最大值
     double value;                   //目标电量
     double alarmValue;              //警戒值
     int decimals;                   //显示小数点后位数
     double step;                    //每次移动的步长
     int borderRadius;               //边框圆角角度
     int bgRadius;                   //背景进度圆角角度
     int headRadius;                 //头部圆角角度
 
     QColor borderColorStart;        //边框渐变开始颜色
     QColor borderColorEnd;          //边框渐变结束颜色
 
     QColor alarmColorStart;         //超警戒值时的渐变开始颜色
     QColor alarmColorEnd;           //超警戒值时的渐变结束颜色
 
     QColor normalColorStart;        //正常时的渐变开始颜色
     QColor normalColorEnd;          //正常时的渐变结束颜色
 
     bool isForward;                 //是否往前移
     double currentValue;            //当前值
     QRectF mainRect;                //主体区域
     QTimer *timer;                  //绘制定时器
 };
 
 #endif // PROGRESS_LABEL_H

 void ProgressLabel::paintEvent(QPaintEvent *)
  {
      //绘制准备工作,启用反锯齿
      QPainter painter(this);
      painter.setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing);
  
      //获取边框区域
      QPointF topLeft(2, 2);
      QPointF bottomRight(width() - 4, height() - 2);
     mainRect = QRectF(topLeft, bottomRight);
     //绘制背景
     drawBg(&painter);
 }
 
 void ProgressLabel::drawBg(QPainter *painter)
 {
     if(!m_IsError)
     {
         painter->save();
         QLinearGradient gradient(QPointF(0, 0), QPointF(0, height()));
         if (currentValue >= alarmValue)
         {
             gradient.setColorAt(0.0, alarmColorStart);
             gradient.setColorAt(1.0, alarmColorEnd);
         }
         else
         {
             gradient.setColorAt(0.0, normalColorStart);
             gradient.setColorAt(1.0, normalColorEnd);
         }
 
         double min = qMin(width(), height());
         int margin =  min / 20;
         double unit = (mainRect.width() - (margin * 2)) / 100;
         double width = currentValue * unit;
         QPointF topLeft(mainRect.topLeft().x() + margin, mainRect.topLeft().y() + margin);
         QPointF bottomRight(width + margin + , mainRect.bottomRight().y() - margin);
         QRectF rect(topLeft, bottomRight);
 
         painter->setPen(Qt::NoPen);
         painter->setBrush(gradient);
         painter->drawRoundedRect(rect, bgRadius, bgRadius);
         painter->restore();
     }
 
     //写进度
     painter->save();
     QPen pen(Qt::SolidLine);
     pen.setWidth(1);
     if(m_IsError)
         pen.setColor(Qt::red);
     else
         pen.setColor(Qt::black);    
     painter->setPen(pen);
     painter->setBrush(Qt::NoBrush);
     if(m_IsError)
         painter->drawText(mainRect, Qt::AlignCenter, m_ErrorText);
     else 
         painter->drawText(mainRect, Qt::AlignCenter, QString("%1%").arg(currentValue, 0, 'f', decimals));
     painter->restore();
 }

timer = new QTimer(this);
timer->setInterval(10);
connect(timer, SIGNAL(timeout()), this, SLOT(updateValue()));

 void ProgressLabel::updateValue()
  {
      if (isForward)
      {
          currentValue -= step;
  
          if (currentValue <= value)
          {
              timer->stop();
             currentValue = value;//保持真实性
         }
     } 
     else
     {
         currentValue += step;
 
         if (currentValue >= value)
         {
             timer->stop();
             currentValue = value;//保持真实性
         }
     }
 
     this->update();
 }

 void ProgressLabel::setValue(double value)
  {
      m_IsError = false;
      //值和当前值一致则无需处理
      if (value == this->value)
          return;
  
      //值小于最小值则取最小值,大于最大值则取最大值
      if (value  maxValue)
         value = maxValue;
 
     if (value > currentValue)
         isForward = false;
     else if (value value = value;
     this->update();
     emit valueChanged(value);
     timer->start();
 }