QT實現秒錶專案

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include<QTime>
#include<QTimer>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:
    void updateTimeAndDisplay();


    void on_btn_start_clicked();

    void on_btn_stop_clicked();

    void on_btn_pause_clicked();

    void on_btn_log_clicked();

private:
    Ui::MainWindow *ui;
    QTimer *ptimer;
    QTime baseTime;
    QString showStr;

};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QString>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    this->ptimer=new QTimer;
    connect(this->ptimer,SIGNAL(timeout()),this,SLOT(updateTimeAndDisplay()));

}

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

void MainWindow::updateTimeAndDisplay(){
    QTime current=QTime::currentTime();
    int t=this->baseTime.msecsTo(current);
    QTime showTime(0,0,0,0);
    showTime=showTime.addMSecs(t);
    showStr=showTime.toString("hh:mm:ss:zzz");
    this->ui->lcdNumber->display(showStr);
}

void MainWindow::on_btn_start_clicked()
{
    this->baseTime=QTime::currentTime();
    this->ptimer->start(1);
    this->ui->btn_start->setEnabled(false);
}

void MainWindow::on_btn_stop_clicked()
{
    if(this->ui->btn_stop->text()=="停止"){
        this->ui->btn_stop->setText("清零");
        this->ptimer->stop();
    }else{
        this->ui->lcdNumber->display("00:00:00:000");
        this->ui->textBrowser->clear();
        this->ui->btn_stop->setText("停止");
        this->ui->btn_start->setEnabled(true);
    }

}

void MainWindow::on_btn_pause_clicked()
{
    static QTime pauseTime;
    if(this->ui->btn_pause->text()=="暫停"){
        pauseTime=QTime::currentTime();
        this->ptimer->stop();
        this->ui->btn_pause->setText("繼續");
    }else{
        QTime cut=QTime::currentTime();
        int t=pauseTime.msecsTo(cut);
        this->baseTime=this->baseTime.addMSecs(t);
        this->ptimer->start(1);
        this->ui->btn_pause->setText("暫停");

    }


}

void MainWindow::on_btn_log_clicked()
{
    this->ui->textBrowser->append(this->showStr);
}

#include "mainwindow.h"
#include <QApplication>

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

    return a.exec();
}