Qt - 电子时钟QTime、QTimer、QLCDNumber

电子时钟QTime、QTimer、QLCDNumber

新建桌面应用程序,项目名LCDClock,类名Clock，基类QDialog,取消产生界面文件
当前项目添加C++类DigitalClock，基类QLCDNumber
编辑digitalclock.h文件

Digitalclock.cpp编辑构造函数及添加事件定义



编辑main.cpp文件

具体操作

具体代码

未雨绸缪

clock.h

#ifndef CLOCK_H
#define CLOCK_H

#include <QDialog>

class Clock : public QDialog
{
    Q_OBJECT

public:
    Clock(QWidget *parent = 0);
    ~Clock();
};

#endif // CLOCK_H

clock.cpp

#include "clock.h"

Clock::Clock(QWidget *parent)
    : QDialog(parent)
{
}

Clock::~Clock()
{

}

digitalclock.h

#ifndef DIGITALCLOCK_H
#define DIGITALCLOCK_H
#include <QLCDNumber>

class DigitalClock : public QLCDNumber
{
    Q_OBJECT
public:
    DigitalClock(QWidget *parent = 0);

protected:
    void mousePressEvent(QMouseEvent *event); //鼠标按下事件
    void mouseMoveEvent(QMouseEvent *event);  //鼠标移动事件

private slots:
    void showTime(); //显示当前时间
private:
    QPoint m_dragPosition; //保存鼠标点相对电子钟表窗体左上角的偏移值
    bool m_showColon;      //钟表显示 " : "
};

#endif // DIGITALCLOCK_H

digitalclock.cpp

#include "digitalclock.h"
#include <QTimer>
#include <QTime>
#include <QMouseEvent>

DigitalClock::DigitalClock(QWidget *parent):QLCDNumber(parent)
{
    //设置蓝色背景
    QPalette p = palette();
    p.setColor(QPalette::Window, Qt::blue);
    setPalette(p);

    //无边框窗体风格
    setWindowFlags(Qt::FramelessWindowHint);

    //窗体透明度
    setWindowOpacity(0.5);

    QTimer *timer = new QTimer(this);
    connect(timer, &QTimer::timeout, this, &DigitalClock::showTime);
    timer->start(1000); //周期为1000毫秒(1秒)


    showTime();
    resize(150, 60);
    m_showColon = true;
}

void DigitalClock::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton)
    {
        m_dragPosition = event->globalPos()  //鼠标相对屏幕左上角的位置
                - frameGeometry().topLeft(); //时钟窗体左上角位置
        event->accept();
    }

    if (event->button() == Qt::RightButton)
    {
        close();
    }
}

void DigitalClock::mouseMoveEvent(QMouseEvent *event)
{
    if (event->button() & Qt::LeftButton)
    {
        move(event->globalPos() - m_dragPosition);
        event->accept();
    }
}

void DigitalClock::showTime()
{
    QTime time = QTime::currentTime();
    QString strTime = time.toString("hh:mm");
    if (m_showColon)
    {
        strTime[2] = ':';
    }
    else
    {
        strTime[2] = ' ';
    }

    display(strTime);
    m_showColon = !m_showColon;
}

main.cpp

#include "clock.h"
#include <QApplication>
#include "digitalclock.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    DigitalClock w;
    w.show();

    return a.exec();
}

结语:

时间: 2020-08-12