Qt：实现一个模拟时钟

客官°小女子只卖身不卖艺 2023-01-12 11:47 166阅读 0赞

1、创建QtGUI应用，基类选择QWidget，取消创建界面，类名Anolog Clock

2、analogclock.h头文件：

#ifndef ANALOGCLOCK_H
    #define ANALOGCLOCK_H
    
    #include <QWidget>
    #include <QPainter>
    
    class AnalogClock : public QWidget
    {
        Q_OBJECT
    
    public:
        AnalogClock(QWidget *parent = 0);
        ~AnalogClock();
    
    protected:
        void paintEvent(QPaintEvent *event);
    };
    
    #endif // ANALOGCLOCK_H

analogclock.cpp：

#include "analogclock.h"
    #include <QtWidgets>
    AnalogClock::AnalogClock(QWidget *parent)
        : QWidget(parent)
    {
       QTimer *timer = new QTimer(this);
       connect(timer, SIGNAL(timeout()), this, SLOT(update()));
       timer->start(1000);
    
       setWindowTitle(tr("Analog Clock"));
       resize(200, 200);
    }
    
    void AnalogClock::paintEvent(QPaintEvent *event)
    {
        static const QPoint hourHand[3] = {
            QPoint(7, 8),
            QPoint(-7, 8),
            QPoint(0, -40)
        };
        static const QPoint minuteHand[3] = {
            QPoint(7, 8),
            QPoint(-7, 8),
            QPoint(0, -70)
        };
        static const QPoint secondHand[3] = {
            QPoint(7, 8),
            QPoint(-7, 8),
            QPoint(0, -90)
        };
    
        QColor hourColor(127, 0, 127);
        QColor minuteColor(0, 127, 127, 191);
        QColor secondColor(0, 12, 127, 127);
    
        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(hourHand, 3);
        painter.restore();
    
        painter.setPen(hourColor);  //画刻度
        for (int i = 0; i < 12; ++i) {
            painter.drawLine(88, 0, 96, 0);
            painter.rotate(30.0);
        }
    
        //-----画分钟-------
        painter.setPen(Qt::NoPen);
        painter.setBrush(minuteColor);
    
        painter.save();
        painter.rotate(6.0 * (time.minute() + time.second() / 60.0));
        painter.drawConvexPolygon(minuteHand, 3);
        painter.restore();
    
        painter.setPen(minuteColor);
        for (int j = 0; j < 60; ++j) {
            if ((j % 5) != 0)
                painter.drawLine(92, 0, 96, 0);
            painter.rotate(6.0);
        }
    
        //-----画秒钟
        painter.setPen(Qt::NoPen);
        painter.setBrush(secondColor);
    
        painter.save();
        painter.rotate(6.0 * time.second());
        painter.drawConvexPolygon(secondHand, 3);
        painter.restore();
    
        painter.end();
    
    
    }
    
    AnalogClock::~AnalogClock()
    {
    
    }

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[1c3031cf3aba3f89e887b7c2807f7f9e.png]: /images/20221119/c6acf3ce8ce94e32b7b6d59f9b1fdc08.png