QT實(shí)現(xiàn)簡單時(shí)鐘效果

更新時(shí)間：2020年05月30日 08:44:02 作者：師子文

這篇文章主要為大家詳細(xì)介紹了QT實(shí)現(xiàn)簡單時(shí)鐘效果，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了QT實(shí)現(xiàn)簡單時(shí)鐘效果的具體代碼，供大家參考，具體內(nèi)容如下

先上效果圖：

預(yù)備知識：

一.鐘表實(shí)現(xiàn)原理

設(shè)置定時(shí)器timer，每隔1000毫秒（即1s）發(fā)送timeout()信號到槽函數(shù)update（），重繪事件函數(shù)paintEvent(QPaintEventevent)

二.鐘表的繪制方法

拆分鐘表：表盤數(shù)字刻度線指針

paintEvent(QPaintEventevent)

1.設(shè)置定時(shí)器，時(shí)間間隔為1000毫秒，并且將定時(shí)器時(shí)間與update函數(shù)關(guān)聯(lián)為信號和槽，定時(shí)器每隔1秒發(fā)送一個(gè)信號
2.繪制時(shí)針分針秒針的形狀。

// 時(shí)針、分針、秒針 - 多邊形
 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.繪制時(shí)針和時(shí)刻度線

 // 繪制時(shí)針
 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);
  // 繪制時(shí)刻度線
 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);

下面是一些基礎(chǔ)的繪圖函數(shù)：

drawPoint() 繪制點(diǎn)
drawLine() 繪制線
drawRect() 繪制矩形
drawEllipse() 繪制橢圓（繪制圓也是此函數(shù)）
drawConvexPolygon() 繪制凸多邊形
drawText（）編制文本

特別的，我們還會經(jīng)常用到
QPen：繪制幾何圖形的邊緣，可繪制顏色，寬度，線的風(fēng)格等
QBrush：用于幾何圖形的調(diào)色板與填充
則可借用setPen（）來當(dāng)做畫筆來使用。
setBrush（）來當(dāng)做填充器使用來填充顏色。
setPen(color)；
然后我們的繪制將會用此顏色的畫筆來繪制圖形邊緣。
setBrush(color)；

主要代碼展示：

void Widget::drawhourhand(QPainter*painter)
{
 QTime time=QTime::currentTime();
 painter->setBrush(Qt::blue);//畫刷，填充
 painter->setPen(Qt::Dense7Pattern);//畫筆，制作廓線
 painter->save();
 painter->rotate(30.0*(time.hour()+time.minute()/60));//使得指針旋轉(zhuǎn)到當(dāng)前時(shí)間位置
 painter->drawConvexPolygon(hourhand,4);;//繪制時(shí)針（凸多邊形）
 painter->restore();//與save連著用 繪制圖形后復(fù)位坐標(biāo)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);//畫刷，填充
 painter->setPen(Qt::Dense7Pattern);//畫筆，制作廓線
 painter->save();
 painter->rotate(30.0*(time.hour()+time.minute()/60));//使得指針旋轉(zhuǎn)到當(dāng)前時(shí)間位置
 painter->drawConvexPolygon(hourhand,4);;//繪制時(shí)針（凸多邊形）
 painter->restore();//與save連著用 繪制圖形后復(fù)位坐標(biāo)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);//截取這么大的面積
 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);//反走樣
 int side=qMin(width(),height());
 painter.setWindow(0,0,230,230);//原本截取放大的面積區(qū)域多大
 painter.setViewport(96,0,side,side);//映射到新的區(qū)域面積多大
 painter.translate(100,100);//重新設(shè)定坐標(biāo)原點(diǎn)
 drawhourhand(&painter);
 drawminutehand(&painter);
 drawsecondhand(&painter);
 drawclockdial(&painter);
 QString timeStr= QTime::currentTime().toString(); //繪制當(dāng)前的電子時(shí)間
 painter.setPen(Qt::white);
 painter.drawText(-20,30,80,30,0,timeStr);
 painter.setBrush(Qt::black);
 painter.drawEllipse(QPoint(0,0),3,3);//中間畫個(gè)小圓點(diǎn)
 // QTransform Transform;
 // Transform.rotate(90);
 // painter.setTransform(Transform);
 painter.drawText(-53,-30,QStringLiteral("老子利指導(dǎo)，殺人先看表"));
}
void Widget::drawclockdial(QPainter*painter)
{
 hourhandpen.setColor(Qt::white);
 hourhandpen.setWidth(2.0);//設(shè)置小時(shí)刻度線為粗黑
 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);//原點(diǎn)變了
  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();
 }


}

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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