Qt自定义控件--等待提示（QProgressIndicator ）

一、效果展示

原理详解请参考：​​Qt定时器使用总结+动画实例​​

二、源码

#ifndef
#define

#include <QWidget>
#include <QColor>
#include <QDesktopWidget>
#include <QApplication>

class QProgressIndicator : public QWidget
{
    Q_OBJECT
    Q_PROPERTY(int delay READ animationDelay WRITE setAnimationDelay)
    Q_PROPERTY(bool displayedWhenStopped READ isDisplayedWhenStopped WRITE setDisplayedWhenStopped)
    Q_PROPERTY(QColor color READ color WRITE setColor)
public:
    QProgressIndicator(QWidget* parent = 0);

    int animationDelay() const { return m_delay; }
    bool isAnimated () const;
    bool isDisplayedWhenStopped() const;
    const QColor & color() const { return m_color; }

    virtual QSize sizeHint() const;
    int heightForWidth(int w) const;
    
public slots:
   
    void startAnimation();
    void stopAnimation();
    void setAnimationDelay(int delay);
    void setDisplayedWhenStopped(bool state);
    void setColor(const QColor & color);
    
protected:
    virtual void timerEvent(QTimerEvent * event);
    virtual void paintEvent(QPaintEvent * event);
    
private:
    int m_angle;
    int m_timerId;
    int m_delay;
    bool m_displayedWhenStopped;
    QColor m_color;
};

#endif// QPROGRESSINDICATOR_H

#include "qprogressindicator.h"

#include <QPainter>

QProgressIndicator::QProgressIndicator(QWidget* parent)
    : QWidget(parent),
      m_angle(0),
      m_timerId(-1),
      m_delay(40),
      m_displayedWhenStopped(false),
      m_color(Qt::black)
{
    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
    setFocusPolicy(Qt::NoFocus);

    setWindowFlags(Qt::FramelessWindowHint | Qt::Tool | Qt::WindowStaysOnTopHint); //设置窗体无标题栏，隐藏任务栏，霸道显示在最顶层
    setAttribute(Qt::WA_TranslucentBackground); //设置面板透明
    showNormal();

    this->setFixedSize(200,200); //固定大小
    QDesktopWidget *pDesk = QApplication::desktop(); //居中显示
    this->move((pDesk->width() - this->width()) / 2, (pDesk->height() - this->height()) / 2);
}

bool QProgressIndicator::isAnimated () const
{
    return (m_timerId != -1);
}

void QProgressIndicator::setDisplayedWhenStopped(bool state)
{
    m_displayedWhenStopped = state;

    update();
}

bool QProgressIndicator::isDisplayedWhenStopped() const
{
    return m_displayedWhenStopped;
}

void QProgressIndicator::startAnimation()
{
    m_angle = 0;

    if (m_timerId == -1)
        m_timerId = startTimer(m_delay);
}

void QProgressIndicator::stopAnimation()
{
    if (m_timerId != -1)
        killTimer(m_timerId);

    m_timerId = -1;

    update();
}

void QProgressIndicator::setAnimationDelay(int delay)
{
    if (m_timerId != -1)
        killTimer(m_timerId);

    m_delay = delay;

    if (m_timerId != -1)
        m_timerId = startTimer(m_delay);
}

void QProgressIndicator::setColor(const QColor & color)
{
    m_color = color;

    update();
}

QSize QProgressIndicator::sizeHint() const
{
    return QSize(20,20);
}

int QProgressIndicator::heightForWidth(int w) const
{
    return w;
}

void QProgressIndicator::timerEvent(QTimerEvent * /*event*/)
{
    m_angle = (m_angle+30)%360;

    update();
}

void QProgressIndicator::paintEvent(QPaintEvent * event)
{
    Q_UNUSED(event)

    if (!m_displayedWhenStopped && !isAnimated())
        return;

    int width = qMin(this->width(), this->height());

    QPainter p(this);
    p.setRenderHint(QPainter::Antialiasing);

    int outerRadius = (width-1)*0.5;
    int innerRadius = (width-1)*0.5*0.38;

    int capsuleHeight = outerRadius - innerRadius;
    int capsuleWidth  = (width > 32 ) ? capsuleHeight *.23 : capsuleHeight *.35;
    int capsuleRadius = capsuleWidth/2;

    for (int i=0; i<12; i++)
    {
        QColor color = m_color;
        color.setAlphaF(1.0f - (i/12.0f));
        p.setPen(Qt::NoPen);
        p.setBrush(color);
        p.save();
        p.translate(rect().center());
        p.rotate(m_angle - i*30.0f);
        p.drawRoundedRect(-capsuleWidth*0.5, -(innerRadius+capsuleHeight), capsuleWidth, capsuleHeight, capsuleRadius, capsuleRadius);
        p.restore();
    }
}