Qt5 学习之路示例：时钟

这次任务要完成Qt5时钟代码编写

一、电子钟设计

见https://blog.csdn.net/fjqlldg/article/details/105695207

二、完成图形钟的代码编写

1、在头文件中添加代码

2、在cpp文件中完成功能

 QRectF Clock::textRectF(double radius, int pointSize, double angle) {     QRectF rectF;     rectF.setX(radius*qCos(angle*M_PI/180.0) - pointSize*2);     rectF.setY(radius*qSin(angle*M_PI/180.0) - pointSize/2.0);     rectF.setWidth(pointSize*4);     rectF.setHeight(pointSize);     return rectF;  }  void Clock::paintEvent(QPaintEvent *event) {     Q_UNUSED(event);       // 时针、分针、秒针位置 - 多边形     static const QPoint hourHand[3] = {         QPoint(7, 8),         QPoint(-7, 8),         QPoint(0, -30)     };     static const QPoint minuteHand[3] = {         QPoint(7, 8),         QPoint(-7, 8),         QPoint(0, -65)     };      static const QPoint secondHand[3] = {         QPoint(7, 8),         QPoint(-7, 8),         QPoint(0, -80)     };      // 时针、分针、秒针颜色     QColor hourColor(200, 100, 0, 200);     QColor minuteColor(0, 127, 127, 150);     QColor secondColor(0, 160, 230, 150);      int side = qMin(width(), height());     QTime time = QTime::currentTime();      QPainter painter(this);     painter.setRenderHint(QPainter::Antialiasing);     // 平移坐标系原点至中心点     painter.translate(width() / 2, height() /2.5);     // 缩放     painter.scale(side / 250.0, side / 250.0);      // 绘制时针     painter.setPen(Qt::NoPen);     painter.setBrush(hourColor);      painter.save();     // 每圈360° = 12h 即：旋转角度 = 小时数 * 30°     painter.rotate(30.0 * ((time.hour() + time.minute() / 60.0)));     painter.drawConvexPolygon(hourHand, 3);     painter.restore();      painter.setPen(hourColor);      // 绘制小时线 （360度 / 12 = 30度）     for (int i = 0; i < 12; ++i) {         painter.drawLine(88, 0, 96, 0);         painter.rotate(30.0);     }      int radius = 100;     QFont font = painter.font();     font.setBold(true);     painter.setFont(font);     int pointSize = font.pointSize();      // 绘制小时文本     int nHour = 0;     for (int i = 0; i < 12; ++i) {         nHour = i + 3;         if (nHour > 12)             nHour -= 12;         painter.drawText(textRectF(radius*0.8, pointSize, i * 30), Qt::AlignCenter, QString::number(nHour));     }      // 绘制分针     painter.setPen(Qt::NoPen);     painter.setBrush(minuteColor);      painter.save();     // 每圈360° = 60m 即：旋转角度 = 分钟数 * 6°     painter.rotate(6.0 * (time.minute() + time.second() / 60.0));     painter.drawConvexPolygon(minuteHand, 3);     painter.restore();      painter.setPen(minuteColor);      // 绘制分钟线 （360度 / 60 = 6度）     for (int j = 0; j < 60; ++j) {         if ((j % 5) != 0)             painter.drawLine(92, 0, 96, 0);         painter.rotate(6.0);     }      // 绘制秒针     painter.setPen(Qt::NoPen);     painter.setBrush(secondColor);      painter.save();     // 每圈360° = 60s 即：旋转角度 = 秒数 * 6°     painter.rotate(6.0 * time.second());     painter.drawConvexPolygon(secondHand, 3);     painter.restore(); } 

3、效果图