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
4000
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：