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基于QT5實(shí)現(xiàn)一個(gè)時(shí)鐘桌面

更新時(shí)間：2022年01月21日 14:53:18 作者：樊城

這篇文章主要介紹了利用QT5實(shí)現(xiàn)的一個(gè)時(shí)鐘桌面，文中的示例代碼講解詳細(xì)，對(duì)我們學(xué)習(xí)或工作有一定的幫助，感興趣的小伙伴可以了解一下

介紹

這是一個(gè)簡(jiǎn)單的時(shí)鐘運(yùn)行界面，項(xiàng)目的結(jié)構(gòu)如圖所示，主要包含一個(gè)頭文件：** analogclock.h **，兩個(gè)源文件: ** analogclock.cpp main.cpp **.

看完本教程，你就可以知悉在Windows系統(tǒng)上如何實(shí)現(xiàn)一個(gè)界面程序并部署在Windows系統(tǒng)上。

實(shí)現(xiàn)代碼

clock.pro

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    analogclock.cpp

HEADERS += \
    analogclock.h

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

analogclock.h

#ifndef ANALOGCLOCK_H
#define ANALOGCLOCK_H

#include <QWidget>

class AnalogClock : public QWidget
{
    Q_OBJECT

public:
    AnalogClock(QWidget *parent=0);
protected:
    void paintEvent(QPaintEvent *event) override;
};
#endif // WIDGET_H

analogclock.cpp

#include <QtWidgets>
#include "analogclock.h"
AnalogClock::AnalogClock(QWidget *parent)
    : QWidget(parent)
{
    QTimer *timer = new QTimer(this);
    //實(shí)例一個(gè)QTimer的類
    connect(timer, SIGNAL(timeout()), this, SLOT(update()));
    //監(jiān)控timeout（）信號(hào)是否發(fā)出
    //timeout()表示：This signal is emitted when the timer times out.
    //指計(jì)時(shí)器發(fā)出信號(hào)，即下面的延時(shí)器發(fā)出信號(hào)
    timer->start(1000);//設(shè)置1s的延時(shí)
   /*
    *for a function
    * void QTimer::start(int msec)
    * Starts or restarts the timer with a timeout interval of msec milliseconds.
    * If the timer is already running, it will be stopped and restarted.
    * If singleShot is true, the timer will be activated only once.
    * 單位是毫秒，表示每一秒設(shè)置一個(gè)信號(hào)發(fā)出
    */
    setWindowTitle(tr("Analog Clock"));
    //void setWindowTitle(const QString &)
    resize(200, 200);
    //初始值大小
}
void AnalogClock::paintEvent(QPaintEvent *)
 {
    /*
     *
     *   repaint() or update() was invoked,
     *   the widget was obscured and has now been uncovered, or
     *   many other reasons.
     *
     *
     */
    static const QPoint hourHand[3] = {
        QPoint(7, 8),
        QPoint(-7, 8),
        QPoint(0, -40)
    };//用于繪制時(shí)針的三角形
    static const QPoint minuteHand[3] = {
        QPoint(7, 8),
        QPoint(-7, 8),
        QPoint(0, -60)
    };//用于繪制分針的三角形
    static const QPoint secondHand[3]={
        QPoint(7,8),
        QPoint(-7,8),
        QPoint(0,-90)
    };//用于繪制秒針的三角形

    QColor hourColor(127, 0, 127);
    QColor minuteColor(0, 127, 127, 191);
    //QColor::QColor(int r, int g, int b, int a = 255)a表示透明度
    QColor secondColor(220,20,60,100);
    //為每一個(gè)圖形繪制顏色及透明度

    int side = qMin(width(), height());
    //我認(rèn)為這一句的作用在于找到最小標(biāo)出，用于坐標(biāo)系的繪制

    QTime time = QTime::currentTime();
    qDebug()<<time<<'\n';//用于檢驗(yàn)現(xiàn)在的時(shí)間

    QPainter painter(this);//Qt強(qiáng)大的畫(huà)圖工具
    painter.setRenderHint(QPainter::Antialiasing);// 用于反鋸齒
    //針對(duì)所有的組件，都反鋸齒//表示設(shè)置渲染提示

    painter.translate(width() / 2, height() / 2);//將原點(diǎn)放在中心
    painter.scale(side / 200.0, side / 200.0);//Scales the coordinate system by (sx, sy).標(biāo)尺坐標(biāo)系
    //Qt畫(huà)板的x和y表示什么，x表示橫線嗎，y表示縱線嗎？對(duì)的
    //說(shuō)明橫坐標(biāo)的范圍是-100到100
    //   縱坐標(biāo)的范圍是-100到100

//時(shí)針：
    painter.setPen(Qt::NoPen);//一般用于描邊，Qt::NoPen表示畫(huà)筆沒(méi)有邊界
    painter.setBrush(hourColor);//一般用于填充

    //先將原先的painter存儲(chǔ)起來(lái)，對(duì)目前的painter操作，目前的操作不對(duì)原本的產(chǎn)生影響，即原本不旋轉(zhuǎn)
    painter.save();//首先將原先畫(huà)筆類似于入棧，對(duì)另一個(gè)畫(huà)筆操作
    painter.rotate(30.0 * ((time.hour() + time.minute() / 60.0)));//表示旋轉(zhuǎn)，若缺少painter.save(),會(huì)對(duì)整個(gè)painter類旋轉(zhuǎn)
    painter.drawConvexPolygon(hourHand, 3);//繪制多邊形
    painter.restore();//與painter.save()配套使用


    painter.setPen(hourColor);

    for (int i = 0; i < 12; ++i) {
        painter.drawLine(88, 0, 96, 0);
        painter.rotate(30.0);//畫(huà)橫線，表示時(shí)間示數(shù)的標(biāo)尺
    }//分針和秒針同時(shí)針

//分針：
    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(92, 0, 96, 0);
        painter.rotate(6.0);
    }

//時(shí)針：
    painter.setPen(Qt::NoPen);
    painter.setBrush(secondColor);

    painter.save();
    painter.rotate(6*time.second());
    painter.drawConvexPolygon(secondHand,3);
    painter.restore();


}

main.cpp

#include "analogclock.h"

#include <QApplication>

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