Qt之对话框设计——电子时钟

digiclock.h

#ifndef DIGICLOCK_H
#define DIGICLOCK_H

#include <QLCDNumber>
#include <QPoint>

class DigiClock : public QLCDNumber
{
    Q_OBJECT

public:
    DigiClock(QWidget *parent = 0);
    ~DigiClock();

    void mousePressEvent(QMouseEvent *);
    void mouseMoveEvent(QMouseEvent *);

public slots:
    void showTime();

private:
    QPoint  dragPosition;   //鼠标点击位置相对窗体左上角的偏移量
    bool showColon;     //是否显示“：”
};

#endif // CLOCK_H

digiclock.cpp

#include "digiclock.h"
#include <QPalette>
#include <QTimer>
#include <QTime>
#include <QMouseEvent>

DigiClock::DigiClock(QWidget *parent)
    : QLCDNumber(parent)
{
    QPalette plt;   //实例化调色板对象
    plt.setColor(QPalette::Window,Qt::blue);
    setPalette(plt);

    setWindowFlags(Qt::FramelessWindowHint);

    setWindowOpacity(0.5);      //设置不透明度

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

    showTime();

    resize(150,60);
    showColon = true;
}

DigiClock::~DigiClock()
{

}

void DigiClock::showTime()
{
    QTime time = QTime::currentTime();
    QString text = time.toString("hh:mm");
    if(showColon)
    {
        text[2] = ':';
        showColon = false;
    }
    else
    {
        text[2] = ' ';
        showColon = true;
    }
    display(text);
}

void DigiClock::mousePressEvent(QMouseEvent * e)
{
    if (e->button() == Qt::LeftButton)
    {
        dragPosition = e->globalPos() - frameGeometry().topLeft();
        e->accept();
    }
    if(e->button() == Qt::RightButton)
    {
        close();
    }
}

void DigiClock::mouseMoveEvent(QMouseEvent * e)
{
    if(e->buttons() & Qt::LeftButton)
    {
        move(e->globalPos() - dragPosition);
        e->accept();
    }
}