QT实现简单时钟效果
师子文 人气:1本文实例为大家分享了QT实现简单时钟效果的具体代码,供大家参考,具体内容如下
先上效果图:
预备知识:
一.钟表实现原理
设置定时器timer,每隔1000毫秒(即1s)发送timeout()信号到槽函数update(),重绘事件函数paintEvent(QPaintEventevent)
二.钟表的绘制方法
拆分钟表:表盘 数字 刻度线 指针
paintEvent(QPaintEventevent)
1.设置定时器,时间间隔为1000毫秒,并且将定时器时间与update函数关联为信号和槽,定时器每隔1秒发送一个信号
2.绘制时针分针秒针的形状。
// 时针、分针、秒针 - 多边形 static const QPoint hourHand[3] = { QPoint(3, 8), QPoint(-3, 8), QPoint(0, -40) }; static const QPoint minuteHand[3] = { QPoint(3, 8), QPoint(-3, 8), QPoint(0, -65) }; static const QPoint secondHand[3] = { QPoint(3, 8), QPoint(-3, 8), QPoint(0, -80) };
3.绘制时针和时刻度线
// 绘制时针 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); // 绘制时刻度线 for (int i = 0; i < 12; ++i) { painter.drawLine(88, 0, 96, 0); painter.rotate(30.0); } QFont font = painter.font(); font.setBold(true); painter.setFont(font);
下面是一些基础的绘图函数:
drawPoint() 绘制点
drawLine() 绘制线
drawRect() 绘制矩形
drawEllipse() 绘制椭圆(绘制圆也是此函数)
drawConvexPolygon() 绘制凸多边形
drawText() 编制文本
特别的,我们还会经常用到
QPen:绘制几何图形的边缘,可绘制颜色,宽度,线的风格等
QBrush:用于几何图形的调色板与填充
则可借用setPen()来当做画笔来使用。
setBrush()来当做填充器使用来填充颜色。
setPen(color);
然后我们的绘制将会用此颜色的画笔来绘制图形边缘。
setBrush(color);
主要代码展示:
void Widget::drawhourhand(QPainter*painter) { QTime time=QTime::currentTime(); painter->setBrush(Qt::blue);//画刷,填充 painter->setPen(Qt::Dense7Pattern);//画笔,制作廓线 painter->save(); painter->rotate(30.0*(time.hour()+time.minute()/60));//使得指针旋转到当前时间位置 painter->drawConvexPolygon(hourhand,4);;//绘制时针(凸多边形) painter->restore();//与save连着用 绘制图形后复位坐标系 } void Widget::drawminutehand(QPainter*painter) { QTime time=QTime::currentTime(); painter->setBrush(Qt::white); painter->setPen(Qt::Dense5Pattern); painter->save(); painter->rotate(6.0*(time.minute()+time.second()/60.0)); painter->drawConvexPolygon(minutehand,4); painter->restore(); } void Widget::drawsecondhand(QPainter*painter) { QTime time=QTime::currentTime(); painter->setBrush(Qt::red); painter->setPen(Qt::Dense5Pattern); painter->save(); painter->rotate(6*time.second()); painter->drawPolygon(minutehand,4); painter->restore(); } `` ```cpp #include "widget.h" #include "ui_widget.h" Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) { ui->setupUi(this); font.setPixelSize(10); setFont(font); setWindowTitle("THE CLOCK"); resize(1200,820); } Widget::~Widget() { delete ui; } const QPoint Widget::hourhand[4]={ QPoint(5,5),QPoint(0,13),QPoint(-5,5),QPoint(0,-40) }; const QPoint Widget::minutehand[4]={ QPoint(3,5),QPoint(0,16),QPoint(-3,5),QPoint(0,-70) }; const QPoint Widget::secondhand[4]={ QPoint(0,0),QPoint(0,0),QPoint(0,0),QPoint(0,0) }; void Widget::drawhourhand(QPainter*painter) { QTime time=QTime::currentTime(); painter->setBrush(Qt::blue);//画刷,填充 painter->setPen(Qt::Dense7Pattern);//画笔,制作廓线 painter->save(); painter->rotate(30.0*(time.hour()+time.minute()/60));//使得指针旋转到当前时间位置 painter->drawConvexPolygon(hourhand,4);;//绘制时针(凸多边形) painter->restore();//与save连着用 绘制图形后复位坐标系 } void Widget::drawminutehand(QPainter*painter) { QTime time=QTime::currentTime(); painter->setBrush(Qt::white); painter->setPen(Qt::Dense5Pattern); painter->save(); painter->rotate(6.0*(time.minute()+time.second()/60.0)); painter->drawConvexPolygon(minutehand,4); painter->restore(); } void Widget::drawsecondhand(QPainter*painter) { QTime time=QTime::currentTime(); painter->setBrush(Qt::red); painter->setPen(Qt::Dense5Pattern); painter->save(); painter->rotate(6.0*time.second()); painter->drawPolygon(minutehand,4); painter->restore(); } void Widget::paintEvent(QPaintEvent*event) { QPainter painter(this); QTimer*timer=new QTimer(this); timer->start(1000); connect(timer,SIGNAL(timeout()),this,SLOT(update())); QPixmap map(":/new/prefix1/timg (1).jfif"); QRect q(0,0,1200,800);//截取这么大的面积 QRect q2(0,0,width(),height());//放到指定大小的框中 painter.drawPixmap(q2,map,q); painter.setRenderHint(QPainter::Antialiasing,true);//反走样 int side=qMin(width(),height()); painter.setWindow(0,0,230,230);//原本截取放大的面积区域多大 painter.setViewport(96,0,side,side);//映射到新的区域面积多大 painter.translate(100,100);//重新设定坐标原点 drawhourhand(&painter); drawminutehand(&painter); drawsecondhand(&painter); drawclockdial(&painter); QString timeStr= QTime::currentTime().toString(); //绘制当前的电子时间 painter.setPen(Qt::white); painter.drawText(-20,30,80,30,0,timeStr); painter.setBrush(Qt::black); painter.drawEllipse(QPoint(0,0),3,3);//中间画个小圆点 // QTransform Transform; // Transform.rotate(90); // painter.setTransform(Transform); painter.drawText(-53,-30,QStringLiteral("老子利指导,杀人先看表")); } void Widget::drawclockdial(QPainter*painter) { hourhandpen.setColor(Qt::white); hourhandpen.setWidth(2.0);//设置小时刻度线为粗黑 minutehandpen.setColor(Qt::white); for(int i=1;i<=60;i++) { painter->save(); painter->rotate(6*i); if(i%5==0) { painter->setPen(hourhandpen); painter->drawLine(0,-98,0,-82);//原点变了 painter->drawText(-20,-82,40,40,Qt::AlignHCenter|Qt::AlignTop,QString::number(i/5)); } else { painter->setPen(minutehandpen); painter->drawLine(0,-98,0,-88); } painter->restore(); } }
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