Qt：简易时钟（圆盘+QLCDNumber）

一、效果展示

简单实现时钟（圆盘+QLCDNumber），大小刻度，数字等。

 

二、实现

.pro

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    mainwindow.h

FORMS += \
    mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

RESOURCES += \
    image.qrc

---

.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 
#include 

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
    void paintEvent(QPaintEvent *event);
    bool showColon = false;
public slots:
    void countTime();

private:
    Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include
#include
#include
#include

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(update()));
    connect(timer, SIGNAL(timeout()), this, SLOT(countTime()));
    timer->start(1000);
    countTime();

    setWindowTitle(tr("Clock_by_Xr"));
    setFixedSize(800, 400);

}

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

void MainWindow::paintEvent(QPaintEvent *event){
    static QPoint hourHand[3] = {
        QPoint(5, 3),
        QPoint(-5, 3),
        QPoint(0, -30)
    };
    static QPoint minuteHand[3] = {
        QPoint(4, 6),
        QPoint(-4, 6),
        QPoint(0, -45)
    };
    static QPoint secondHand[3] = {
        QPoint(2, 10),
        QPoint(-2, 10),
        QPoint(0, -60)
    };


    //颜色
    QColor hourColor(0, 185, 211, 238);
    QColor minuteColor(0, 96, 123, 139);
    QColor secondColor(0, 176, 226, 255);

    int side = qMin(width(), height());
    QTime time = QTime::currentTime();

    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);
    //表盘
    QBrush brush1(QColor(164,211,238));
    QPen pen1(QColor(164,211,238));
    painter.setBrush(brush1);
    painter.setPen(pen1);
    painter.drawEllipse(QPoint(200,200),200/3*2,200/3*2);

    QBrush brush2(QColor(245,245,245));
    QPen pen2(QColor(245,245,245));
    painter.setBrush(brush2);
    painter.setPen(pen2);
    painter.drawEllipse(QPoint(200,200),194/3*2,194/3*2);

    QBrush brush3(QColor(250,250,250));
    QPen pen3(QColor(250,250,250));
    painter.setBrush(brush3);
    painter.setPen(pen3);
    painter.drawEllipse(QPoint(200,200),183/3*2,183/3*2);

    QBrush brush4(QColor(255,255,255));
    QPen pen4(QColor(255,255,255));
    painter.setBrush(brush4);
    painter.setPen(pen4);
    painter.drawEllipse(QPoint(200,200),175/3*2,175/3*2);

    painter.setRenderHint(QPainter::Antialiasing);
    painter.translate(width()/4, height()/2);
    painter.scale(side/200.0, side/200.0);

    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();

    //刻度
    painter.setPen(hourColor);
    for (int i = 0; i < 12; ++i) {

        painter.rotate(30.0);
        painter.drawLine(66,0,72,0);
        painter.drawText(-15, -65, 30, 30,Qt::AlignHCenter,QString::number(i+1));
    }

    //分钟
    painter.setPen(Qt::NoPen);
    painter.setBrush(minuteColor);

    painter.save();
    painter.rotate(6.0 * (time.minute() + time.second() / 60.0));
    painter.drawConvexPolygon(minuteHand, 3);
    painter.restore();

    painter.setPen(minuteColor);
    for (int j = 0; j < 60; ++j) {
        if ((j % 5) != 0)
            painter.drawLine(68, 0, 72, 0);
        painter.rotate(6.0);
    }

    //秒钟
    painter.setPen(Qt::NoPen);
    painter.setBrush(secondColor);

    painter.save();
    painter.rotate(6.0 * time.second());
    painter.drawConvexPolygon(secondHand, 3);
    painter.restore();

    painter.end();
}

void MainWindow::countTime(){
    QTime t = QTime::currentTime();
    QString text=t.toString("hh:mm:ss");
    if(showColon){
        text[2] = ':';
        text[5] = ':';
        showColon = false;
    }
    else{
        text[2] = ' ';
        text[5] = ' ';
        showColon = true;
    }
    ui->lcdNumber->display(text);
    ui->lcdNumber_2->display(text);
}