实现方法

主窗口QDialog调用QLCDNumber窗口

实现效果

代码

头文件

dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

QT_BEGIN_NAMESPACE
namespace Ui { class Dialog; }
QT_END_NAMESPACE

class Dialog : public QDialog
{
    Q_OBJECT

public:
    Dialog(QWidget *parent = nullptr);
    ~Dialog();

private:
    Ui::Dialog *ui;
};
#endif // DIALOG_H

digiclock.h

#ifndef DIGICLOCK_H
#define DIGICLOCK_H
#include<QLCDNumber>


class DigiClock : public QLCDNumber
{
    Q_OBJECT

public:
    DigiClock(QWidget *parent=0);
    void mousePressEvent(QMouseEvent *);
    void mouseMoveEvent(QMouseEvent *);
public slots:
    void showTime();
private:
    QPoint dragPosition;
    bool showColon;
};

#endif // DIGICLOCK_H

源文件

main.cpp

#include "dialog.h"
#include"digiclock.h"
#include <QApplication>

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

dialog.cpp

#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent)
    : QDialog(parent)
    , ui(new Ui::Dialog)
{
    ui->setupUi(this);
}

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

digiclock.cpp

#include <QTimer>
#include<QTime>
#include<QMouseEvent>
#include "digiclock.h"
//#include "ui_digiclock.h"

DigiClock::DigiClock(QWidget *parent):QLCDNumber(parent)
{
    QPalette p=palette();
    p.setColor(QPalette::Window,Qt::blue);
    setPalette(p);
    setWindowFlags(Qt::FramelessWindowHint);
    setWindowOpacity(0.5);
    QTimer *timer = new QTimer(this);
    connect(timer,SIGNAL(timeout()),this,SLOT(showTime()));
    timer->start(1000);
    showTime();
    resize(150,60);
    showColon=true;

}

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 *event)
    {
        if(event->button()==Qt::LeftButton)
        {
            dragPosition=event->globalPos() -frameGeometry().topLeft();
            event->accept();
        }
        if(event->button()==Qt::RightButton)

        {
            close();
        }
    }

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




//QDialog::QDialog(QWidget *parent)
//    : QDialog(parent)
//    , ui(new Ui::QDialog)
//{
//    ui->setupUi(this);
//}

//QDialog::~QDialog()
//{
//    delete ui;
//}