C++电子时钟类.......

C++设计一个电子时钟类，包含年月日，时分秒等属性，由时间类和日期类组合而成，实现并测试这个类。正确显示，年/月/日，时:分:秒。

时间要自动跑么？

class Time  //时间类
{
    private:
        int nHour; //小时
        int nMin;  //分钟
        int nSec;  //秒
    public:
        Time() {nHour = 0;nMin = 0;nSec = 0;} //默认无参构造函数，将属性都初始化为0
        Time(int h,int m,int s) {nHour = h;nMin = m;nSec = s;} //带参构造函数，在定义类对象时可以直接赋予初始值
        void SetTime(int h,int m,int s) {nHour = h;nMin = m;nSec = s;} //设置时间，可随时修改类属性值
        void print() {cout<<nHour<<":"<<nMin<<":"<<nSec;}   //打印函数，按照 时:分:秒 格式输出
};

class Date  //日期类
{
    private:
        int nYear;    //年份
        int nMonth;    //月份
        int nDay;    //日期
    public:
        Date() {nYear = 0;nMonth = 0;nDay = 0;}  //默认无参构造函数
        Date(int y,int m,int d) {nYear = y;nMonth = m;nDay = d;} //带参构造函数
        void SetDate(int y,int m,int d) {nYear = y;nMonth = m;nDay = d;} //设置日期
        void print() {cout<<nYear<<"/"<<nMonth<<"/"<<nDay;}  //按照 年/月/日 格式输出日期
};

class Clock  //时钟类
{
    private:
        Date date;   //日期对象
        Time time;    //时间对象
    public:
        Clock() {} //默认无参构造函数
        Clock(int year,int month,int day,int hour,int min,int sec)  //带参构造函数
        {
            date.SetDate(year,month,day);  //分别将参数传递给成员类对象
            time.SetTime(hour,min,sec);
        }
        void SetDateTime(int year,int month,int day,int hour,int min,int sec) //设置日期时间函数
        {
            date.SetDate(year,month,day);
            time.SetTime(hour,min,sec);
        }
        void print()  //打印日期时间
        {
            date.print();
            cout<<" ";
            time.print();
            cout<<endl;
        }  
};

int main()
{
    Clock clock;   //创建一个时钟类对象
    SYSTEMTIME st;
    GetLocalTime(&st);  //获取操作系统中的当前时间
    clock.SetDateTime(st.wYear,st.wMonth,st.wDay,st.wHour,st.wMinute,st.wSecond); //将当前时间传递给时钟类对象
    clock.print(); //显示当前的日期时间信息
    return 0;
}

#include <Windows.h>
#include <ctime>
#include <iostream>
using namespace std;

typedef void(*BACKCALLFUNC)(void *);  //定时器回调函数申明

class Time
{
    private:
        int nHour;
        int nMin;
        int nSec;
    public:
        Time() {nHour = 0;nMin = 0;nSec = 0;}
        Time(int h,int m,int s) {nHour = h;nMin = m;nSec = s;}
        void SetTime(int h,int m,int s) {nHour = h;nMin = m;nSec = s;}
        void print() {cout<<nHour<<":"<<nMin<<":"<<nSec;}  
};
class Date
{
    private:
        int nYear;
        int nMonth;
        int nDay;
    public:
        Date() {nYear = 0;nMonth = 0;nDay = 0;}
        Date(int y,int m,int d) {nYear = y;nMonth = m;nDay = d;}
        void SetDate(int y,int m,int d) {nYear = y;nMonth = m;nDay = d;}
        void print() {cout<<nYear<<"/"<<nMonth<<"/"<<nDay;}
};
class Clock
{
    private:
        Date date;
        Time time;
    public:
        Clock() {}
        Clock(int year,int month,int day,int hour,int min,int sec)
        {
            date.SetDate(year,month,day);
            time.SetTime(hour,min,sec);
        }
        void SetDateTime(int year,int month,int day,int hour,int min,int sec)
        {
            date.SetDate(year,month,day);
            time.SetTime(hour,min,sec);
        }
        void print() 
        {
            date.print();
            cout<<" ";
            time.print();
            cout<<endl;
        }  
};

void backcallfunc(void *arg)  //定时器回调函数
{
	system("cls");
	Clock clock;
	SYSTEMTIME st;
	GetLocalTime(&st);
	clock.SetDateTime(st.wYear,st.wMonth,st.wDay,st.wHour,st.wMinute,st.wSecond);
	clock.print();
}

void settimer(unsigned int id, int msec, BACKCALLFUNC backcallfunc)//实现定时器
{
	if (msec < 0) //判断时间段是否满足 >=0
	{
		return;
	}
	clock_t start, finish;
	start = clock();//计时函数
	double totaltime = 0;//定义时间变量
	while (1)
	{
		finish = clock();
		totaltime = (double)(finish - start);
		if (totaltime > msec)
		{
			backcallfunc(&totaltime);
			break;
		}
	}
}

int main()
{
    //不断循环执行定时器，每秒执行一次
	while(1)
		settimer(1, 1000, backcallfunc);
    return 0;
}