Qt4实现钟表的demo

最近刚开始接触Qt，通过查看Qt自带的demo，稍微做了下修改，参考了下：http://www.tudou.com/programs/view/1Nwo0piJcBQ/ 的视频，具体实现如下：

1. 首先安装Qt环境，在此略过。打开Qt Creator

2. 新建一个工程，取名为clock

3. 编辑clock.h头文件

#ifndef CLOCK_H
#define CLOCK_H

#include 

namespace Ui {
class Clock;
}

class Clock : public QWidget
{
    Q_OBJECT
    
public:
    explicit Clock(QWidget *parent = 0);
    ~Clock();
protected:
    void paintEvent(QPaintEvent *);
    
private:
    Ui::Clock *ui;
};

#endif // CLOCK_H

#include 
#include "clock.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Clock w;
    w.show();
    
    return a.exec();
}

#include 
#include "clock.h"
#include "ui_clock.h"

Clock::Clock(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Clock)
{
    ui->setupUi(this);

    QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(update()));
    timer->start(1000);

    setWindowTitle(tr("Clock"));
    resize(200, 200);
}

Clock::~Clock()
{
    delete ui;
}

void Clock::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)
    };

    QColor hourColor(Qt::darkGreen);
    QColor minColor(Qt::darkRed);
    QColor secColor(Qt::black);

    int side = qMin(width(), height());
    QTime time = QTime::currentTime();

    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.translate(width() / 2, height() / 2);
    painter.scale(side / 200.0, side / 200.0);

    painter.setPen(Qt::NoPen);
    painter.setBrush(hourColor);

    painter.save();
    painter.rotate(30.0 * ((time.hour() + time.minute() / 60.0)));
    painter.drawConvexPolygon(hour, 3);
    painter.restore();

    painter.setPen(hourColor);

    for (int i = 0; i <12; i++)
    {
        painter.setPen(Qt::black);
        painter.drawLine(88, 0, 96, 0);
        painter.rotate(30.0);
    }

    painter.setPen(Qt::NoPen);
    painter.setBrush(minColor);

    painter.save();
    painter.rotate(6.0 * (time.minute() + time.second() / 60.0));
    painter.drawConvexPolygon(min, 3);
    painter.restore();

    painter.setPen(minColor);

    for (int j = 0; j <60; j++)
    {
        painter.setPen(Qt::green);
        if ((j % 5) != 0)
            painter.drawLine(92, 0, 96, 0);
        painter.rotate(6.0);
    }

    painter.setPen(Qt::NoPen);
    painter.setBrush(secColor);

    painter.save();
    painter.rotate(6.0 * time.second());
    painter.drawConvexPolygon(sec, 3);
    painter.restore();

}

mingwm10.dll

QtCore4.dll

QtGui4.dll

clock.exe也放到一个文件夹下，在Qt Creator摁下”CRTL+T“,选择release版本即可！

样子如下所示：