QT制作简易时钟

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include 
#include 
#include 
#include 
#include 

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
    void paintEvent(QPaintEvent *event) override;
    //void timerEvent(QTimerEvent *e) override;
private:
    Ui::Widget *ui;
    int m_hour=0;
    int m_min=0;
    int m_sec=0;
    QTimer *timer;
private slots:
    void timeout_slot();
};
#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->resize(600, 600);

    timer = new QTimer(this);
    timer->start(1000);
    connect(timer, &QTimer::timeout, this, &Widget::timeout_slot);
}

Widget::~Widget()
{
    delete ui;
}

void Widget::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);

    QPainterPath painterPath;
    painterPath.addEllipse(100, 100, 400, 400);
    painter.setClipPath(painterPath);  //添加绘制区域，为圆形绘制

    QPixmap pixMap("C:\\Users\\Acer\\Desktop\\qq.jpg");
    painter.drawPixmap(100, 100, 400, 400, pixMap);

    painter.drawEllipse(100, 100, 400, 400);

    QTransform transform;
    transform.translate(300, 300);  //平移坐标原点
    painter.setTransform(transform);

    painter.setPen(Qt::black);
   // painter.drawPoint(250,250);

    for(int i=1;i<=60;i++)
       {
           painter.setPen(Qt::red);
           painter.save();
           painter.rotate(6*i);
           if(i%5==0)
           {
               QLinearGradient linearGradient(0,0,1,1);
               linearGradient.setColorAt(0.0, "#0080FF");
               linearGradient.setColorAt(1.0, "#67CCFF");
               QPen pen(QBrush(linearGradient),2);
               painter.setPen(pen);
               painter.drawLine(0, -198, 0, -182);
               painter.drawText(QPoint(-5, -160), QString::number(i/5));
           }
           else
           {
               painter.setPen(Qt::black);
               painter.drawLine(0, -198, 0, -188);
           }
           painter.restore();
    }
    painter.save();
    painter.setPen(QPen(Qt::blue, 3));  //秒针
    painter.rotate(6*(m_sec+1));  //旋转度数  360度 60秒钟
    painter.drawLine(0,0,0,-170);
    painter.restore();  //旋转完成之后还原

    painter.save();
    painter.setPen(QPen(Qt::green, 4));  //分针
    painter.rotate(6*(m_min));  //60分钟
    painter.drawLine(0, 0, 0, -130);
    painter.restore();

    painter.save();
    painter.setPen(QPen(Qt::red, 5));  //时针
    painter.rotate(30*(m_hour));  //24小时
    painter.drawLine(0, 0, 0, -100);
    painter.restore();
}

void Widget::timeout_slot()
{
    QTime currentTime=QTime::currentTime();

    m_hour=currentTime.hour();
    m_min=currentTime.minute();
    m_sec=currentTime.second();

    update();
}

main.cpp

#include "widget.h"

#include 

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

效果图