Question

c++时钟程序代码

想做一个 有关日历时钟的 程序 功能部分已经写好了 但是问题是怎么从系统中调用 电脑里的 时间程序 用呢？ 希望给我代码 或实例 谢谢各位了
呵呵 再祝各位在新的一年里都有所进步 呵呵
加一句 小弟我只是对c++ 略懂一些 别的 两眼一抹黑 嘿嘿 麻烦各位高手了！

Answer 1

用c++的话还是弄成类比较好的，下面是我的解决方法：

#include <ctime>
#include <cstring>
class Timer
{
private:
static const int size = 50;
std::time_t time;
std::tm localTime;
char Ascll[size];
char flag;
public:
Timer()
{
std::time(&time);
flag = 0;
}
~Timer() {}
const char* printTime()
{
if(!flag)
{
localTime = *std::localtime(&time);
std::strcpy(Ascll, std::asctime(&localTime));
}
flag++;
return Ascll;
}
double timeDiff(Timer* time2) const
{
return difftime(time, time2 -> time);
}
} ;

int main()
{
Timer t1;
for(int i = 0; i < 10000; i++ )
{
cout << i;
}
Timer t2;
std::cout << t1.printTime() << std::endl;
std::cout << t2.printTime() << std::endl;
std::cout << t2.timeDiff(&t1) << std::endl;
return 0;
}

Answer 2

C语言库函数里提供了一套关于时间的函数

time_t t = 0;
char day[20] = {0};
t = time(0);//获取系统时间，此时t存放的是系统时间的秒值(从1970年1月1日0时开始到当前时间）
strftime (day, sizeof(day), "%Y-%m-%d %H:%M:%S", gmtime (&t)); //转换为字符串格式，这里的例子是 年-月-日 时:分:秒

这里给出的是Linux下的例子，需要包含头文件#include <sys/time.h>。
如果是在windows下，你可以自己找找相应的头文件即可

下面是MSDN里关于时间函数的示例，仔细看几遍，相信你以后对时间操作的问题就不会抓瞎了

#include <time.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/timeb.h>
#include <string.h>

void main()
{
char tmpbuf[128], ampm[] = "AM";
time_t ltime;
struct _timeb tstruct;
struct tm *today, *gmt, xmas = { 0, 0, 12, 25, 11, 93 };

/* Set time zone from TZ environment variable. If TZ is not set,
* the operating system is queried to obtain the default value
* for the variable.
*/
_tzset();

/* Display operating system-style date and time. */
_strtime( tmpbuf );
printf( "OS time:\t\t\t\t%s\n", tmpbuf );
_strdate( tmpbuf );
printf( "OS date:\t\t\t\t%s\n", tmpbuf );

/* Get UNIX-style time and display as number and string. */
time( <ime );
printf( "Time in seconds since UTC 1/1/70:\t%ld\n", ltime );
printf( "UNIX time and date:\t\t\t%s", ctime( <ime ) );

/* Display UTC. */
gmt = gmtime( <ime );
printf( "Coordinated universal time:\t\t%s", asctime( gmt ) );

/* Convert to time structure and adjust for PM if necessary. */
today = localtime( <ime );
if( today->tm_hour > 12 )
{
strcpy( ampm, "PM" );
today->tm_hour -= 12;
}
if( today->tm_hour == 0 ) /* Adjust if midnight hour. */
today->tm_hour = 12;

/* Note how pointer addition is used to skip the first 11
* characters and printf is used to trim off terminating
* characters.
*/
printf( "12-hour time:\t\t\t\t%.8s %s\n",
asctime( today ) + 11, ampm );

/* Print additional time information. */
_ftime( &tstruct );
printf( "Plus milliseconds:\t\t\t%u\n", tstruct.millitm );
printf( "Zone difference in seconds from UTC:\t%u\n",
tstruct.timezone );
printf( "Time zone name:\t\t\t\t%s\n", _tzname[0] );
printf( "Daylight savings:\t\t\t%s\n",
tstruct.dstflag ? "YES" : "NO" );

/* Make time for noon on Christmas, 1993. */
if( mktime( &xmas ) != (time_t)-1 )
printf( "Christmas\t\t\t\t%s\n", asctime( &xmas ) );

/* Use time structure to build a customized time string. */
today = localtime( <ime );

/* Use strftime to build a customized time string. */
strftime( tmpbuf, 128,
"Today is %A, day %d of %B in the year %Y.\n", today );
printf( tmpbuf );
}

程序运行结果

OS time: 21:51:03
OS date: 05/03/94
Time in seconds since UTC 1/1/70: 768027063
UNIX time and date: Tue May 03 21:51:03 1994
Coordinated universal time: Wed May 04 04:51:03 1994
12-hour time: 09:51:03 PM
Plus milliseconds: 279
Zone difference in seconds from UTC: 480
Time zone name:
Daylight savings: YES
Christmas Sat Dec 25 12:00:00 1993

Today is Tuesday, day 03 of May in the year 1994.