Qt之实现表针时钟小工具

有时单纯的主界面看起来比较呆板，在上面加入一些动态元素就生动许多。

实现思路是以QDialog为基类，在主窗口上新建子窗口，让子窗口透明化，在子窗口中绘制表盘、时分秒表针等，主窗口移动时，子窗口也跟着移动。

一、实现原理：

利用QTimer计时器，每隔1s触发信号update()进行更新窗口，更新窗口会触发paintEvent(QPaintEvent *)，在绘制事件中利用系统时间对各个指针进行刷新。

二、清单：

PaintClock.h/PaintClock.cpp ：绘制表钟函数，用类实现可降低耦合性

三、调用

1. 调用比较简单，在主窗口构造函数中new出即可：

m_pclock_ = new PaintClock(this);

m_pclock->show();

2. 让表钟窗口随主窗口移动而移动，需重载QDialog的event Filter，在主窗口类中添加：

protected:

    bool eventFilter(QObject *, QEvent *);

bool MyMainUI::eventFilter(QObject *object, QEvent *event)

{

    switch (event->type()) {

    case QEvent::Resize: {

        d->pclock_->move(this->geometry().x()+this->frameGeometry().width()/2.5,

            this->geometry().y()+this->frameGeometry().height()/3);

        break;

    }

    case QEvent::Move: {

        d->pclock_->move(this->geometry().x()+this->frameGeometry().width()/2.5,

            this->geometry().y()+this->frameGeometry().height()/3);

        break;

    }

    default:

        break;

    }

    return false;

}

四、PaintClock.h/PaintClock.cpp具体实现如下：

/**
 \file PaintClock.h

 \author Jack Li
*/

#ifndef PAINTCLOCK_H
#define PAINTCLOCK_H

#include 
#include 


class PaintClock : public QDialog
{
public:
	PaintClock(QWidget *parent);
	~PaintClock();
	
	void show();
	void move(int x, int y);

protected:
	void paintEvent(QPaintEvent * event);

private:
	PaintClock(PaintClock const &);
	void operator=(PaintClock const &);

	struct Private;
	Private * const d; 
};

#endif // PAINTCLOCK_H
/**
  \file PaintClock.cpp

  \author Jack Li
*/

#include "PaintClock.h"

#include 
#include 
#include 
#include 

struct PaintClock::Private
{
	Private(PaintClock * parent)
    {}
	///
	QTimer * timer_;
};


PaintClock::PaintClock(QWidget * parent)
	: QDialog(parent), d(new PaintClock::Private(this))
{	
    /* set initial location */
	setGeometry(parent->geometry().x()+parent->frameGeometry().width()/2.5, 
		parent->geometry().y()+parent->frameGeometry().height()/3, 200, 200);
	/* set windows no frame */	
 	setWindowFlags(Qt::Dialog|Qt::FramelessWindowHint);
 	/* set background translucent */
 	setWindowOpacity(1); 
    setAttribute(Qt::WA_TranslucentBackground);
	
	d->timer_ = new QTimer(this);
    connect(d->timer_, SIGNAL(timeout()), this, SLOT(update()));
	d->timer_->start(1000);
}


PaintClock::~PaintClock()
{
    if (d->timer_)
        delete d->timer_;
	delete d;
}


void PaintClock::move(int x, int y)
{	
	QDialog::move(x, y);
}


void PaintClock::show()
{
	QDialog::show();
}


void PaintClock::paintEvent(QPaintEvent *)
{
    static const QPoint hour[3] = {
        QPoint(7, 8),
        QPoint(-7, 8),
        QPoint(0, -40)
    };
    static const QPoint min[3] = {
        QPoint(7, 8),
        QPoint(-7, 8),
        QPoint(0, -60)
    };
    static const QPoint sec[3] = {
        QPoint(2, 8),
        QPoint(-2, 8),
        QPoint(0, -80)
    };

    QTime time = QTime::currentTime();
    QPainter paint(this); 
	//painter moves to center 
    paint.translate(100, 100);
    //paint.drawLine(0, 0, 100, 100);
    paint.setRenderHint(QPainter::Antialiasing);//set painter antialias
    paint.setBrush(Qt::red);
    paint.setPen(Qt::red);
    paint.save();
    paint.rotate(6.0 * time.second());
    /* paint sec pointer */
    paint.drawConvexPolygon(sec, 4);
    paint.restore();
    paint.setBrush(Qt::blue);
    paint.setPen(Qt::blue);
    paint.save();
    paint.rotate(6.0 * (time.minute() + time.second() /60.0));/* 6(360 / 60) */
    /* paint min pointer */
    paint.drawConvexPolygon(min, 4);
    paint.restore(); 
    paint.setBrush(Qt::black);
    paint.setPen(Qt::black);
    paint.save();
    paint.rotate(30.0 * (time.hour() + time.minute() / 60.0));/* 30(360 / 12) */
    /* paint hour pointer */
    paint.drawConvexPolygon(hour, 4);
    paint.restore();
    /* paint clock dial plate */
    for (int i = 1; i <= 60; i++) {
        paint.rotate(6);/* 6° */
        if (i == 60) {
            paint.save();
            paint.setBrush(Qt::red);
            paint.setPen(Qt::red);
            paint.drawLine(0, -98, 0, -82); /* -98*cos(30).. */
            paint.restore();
        } else if (i == 30) {
            paint.save();
            paint.setBrush(Qt::red);
            paint.setPen(Qt::red);
            paint.drawLine(0, -98, 0, -83); /* -98*cos(30).. */
            paint.restore();
        } else if (i == 45 || i == 15) {
            paint.save();
            paint.setBrush(Qt::yellow);
            paint.setPen(Qt::yellow);
            paint.drawLine(0, -98, 0, -84); /* -98*cos(30).. */
            paint.restore();
        } else if (i %5 == 0) {
            paint.save();
            paint.setBrush(Qt::yellow);
            paint.setPen(Qt::yellow);
            paint.drawLine(0, -98, 0, -86); /* -98*cos(30).. */
            paint.restore();
        } else {
            paint.drawLine(0, -98, 0, -88); /* -98*cos(30).. */
        }
    }
    /* paint number:12,6,9,3 */
    paint.save();
    paint.setBrush(Qt::black);
    paint.setPen(Qt::black);
    QFont* pFont = new QFont("宋体", 11, 75, false);
    paint.setFont(*pFont);
    paint.drawText(QRectF(-8, -80, 25, 15), "12");
    paint.drawText(QRectF(-4, 70, 25, 15), "6");
    paint.drawText(QRectF(-75, -5, 25, 15), "9");
    paint.drawText(QRectF(70, -5, 25, 15), "3");
    delete pFont;
    paint.restore();
}

五、效果图：