Qt设计时钟效果

//(1)绘制线段
painter->drawLine(20,20,100,120);
//画一条(20,20)到(100,120)的线段

//(2)绘制圆或者椭圆
painter->drawEllipse(20,20,210,160);
//第一二个参数表示椭圆外切矩形左上角的坐标，第三四个参数表示外切矩形的宽度和高度

//(3)绘制矩形
painter->drawReact(20,20,210,160);
//第一二个参数表示椭圆外切矩形左上角的坐标，第三四个参数表示矩形的宽度和高度

float radious;//时钟半径

int xSecond,ySecond,xHour,yHour,xMinute,yMinute;
int xCenter,yCenter;// 时钟中心坐标
int second,minute,hour;//时分秒的实际数字
void CalcPostion();//计算指针坐标的函数
void timerEvent(QTimerEvent*);
void paintEvent(QPaintEvent*event);
void drawClockDial(QPainter *painter);

#include "mainwindow.h"
#include<qmath.h>
#include<QPainter>
#define PI 3.14159265

void MainWindow::CalcPostion()
{
 double minuteHandLen,secondHandLen,hourHandLen;
 secondHandLen=radious*0.8;
 minuteHandLen=radious*0.65;
 hourHandLen=radious*0.5;//时分秒针的长度
 //秒针的位置
 xSecond=xCenter+secondHandLen*cos(second*PI/30-PI/2);
 ySecond=yCenter+secondHandLen*sin(second*PI/30-PI/2);
 //分针的位置
 xMinute=xCenter+minuteHandLen*cos(minute*PI/30-PI/2);
 yMinute=xCenter+minuteHandLen*sin(minute*PI/30-PI/2);
 //时针的位置
 xHour=xCenter+hourHandLen*cos((hour+1.0*minute/60)*PI/6-PI/2);
 yHour=yCenter+hourHandLen*sin((hour+1.0*minute/60)*PI/6-PI/2);
}

MainWindow::MainWindow(QWidget *parent)
 : QMainWindow(parent)
{
 radious=200;//半径200
 xCenter=200;
 yCenter=200;//圆心(200,200)
 hour=3,minute=56,second=35;//初试时间3:56:35
 CalcPostion();
 startTimer(100);//方便观察，加速10倍
 resize(400,400);//窗口大小400*400
}

void MainWindow::timerEvent(QTimerEvent *event)
{
 CalcPostion();//计算位置
 second++;
 if(second==60)
 {
 second=0;
 minute++;
 }//分增加
 if (minute==60)
 {
 minute=0;
 hour++;
 }//时增加
 update();
}
void MainWindow::paintEvent(QPaintEvent *event)
{
 QPainter painter(this);
 QPixmap map("://res/01.jpg");//加入表盘
 QRect q(0,0,400,400);
 painter.drawPixmap(q,map,q);
 QPen pen;
 painter.drawEllipse(QPointF(200.0,200.0),radious,radious);//画圆
 painter.drawLine(xCenter,yCenter,xSecond,ySecond);//秒针
 pen.setWidth(2);
 painter.setPen(pen);
 painter.drawLine(xCenter,yCenter,xMinute,yMinute);//分针
 pen.setWidth(4);
 painter.setPen(pen);
 painter.drawLine(xCenter,yCenter,xHour,yHour);//时针
}
MainWindow::~MainWindow()
{
 delete ui;
}

#include "mainwindow.h"

#include <QApplication>

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