vc ＋＋中获取系统小时时间

在VC++中分别获取系统当前小时，分钟，秒的程序代码。谢谢各位高手帮忙

1 使用time_t time( time_t * timer ) 精确到秒

　　计算时间差使用double difftime( time_t timer1, time_t timer0 )

2 使用clock_t clock() 得到的是CPU时间 精确到1/CLOCKS_PER_SEC秒

3 使用DWORD GetTickCount() 得到的是系统运行的时间 精确到毫秒

4 如果使用MFC的CTime类，可以用CTime::GetCurrentTime() 精确到秒

5 要获取高精度时间，可以使用

BOOL QueryPerformanceFrequency(LARGE_INTEGER *lpFrequency)获取系统的计数器的频率

BOOL QueryPerformanceCounter(LARGE_INTEGER *lpPerformanceCount)获取计数器的值

然后用两次计数器的差除以Frequency就得到时间。

GetTickCount()和GetCurrentTime()都只精确到55ms(1个tick就是55ms)。如果要精确到毫秒，应该使用timeGetTime函数或QueryPerformanceCounter函数。具体例子可以参考QA001022 "VC++中使用高精度定时器"、QA001813 "如何在Windows实现准确的定时"和QA004842 "timeGetTime函数延时不准"。

Q:vc++怎样获取系统时间，返回值是什么类型的变量呢？

GetSystemTime返回的是格林威志标准时间

GetLocalTime，和上面用法一样，返回的是你所在地区的时间，中国返回的是北京时间

VOID GetSystemTime(

LPSYSTEMTIME lpSystemTime // address of system time structure

);

函数就可以获得了，其中LPSYSTEMTIME 是个结构体

含：年，月，日，周几，小时，分，秒，毫秒。

以下是Time的MSDN文档:

Compatibility in the Introduction.

Libraries

Return Value

time returns the time in elapsed seconds. There is no error return.

Parameter

timer

Storage location for time

Remarks

The time function returns the number of seconds elapsed since midnight (00:00:00), January 1, 1970, coordinated universal time, according to the system clock. The return value is stored in the location given by timer. This parameter may be NULL, in which case the return value is not stored.

Example

#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 };

_tzset();

_strtime( tmpbuf );

printf( "OS time:\t\t\t\t%s\n", tmpbuf );

_strdate( tmpbuf );

printf( "OS date:\t\t\t\t%s\n", tmpbuf );

time( &ltime );

printf( "Time in seconds since UTC 1/1/70:\t%ld\n", ltime );

printf( "UNIX time and date:\t\t\t%s", ctime( &ltime ) );

gmt = gmtime( &ltime );

printf( "Coordinated universal time:\t\t%s", asctime( gmt ) );

today = localtime( &ltime );

if( today->tm_hour > 12 )

{

strcpy( ampm, "PM" );

today->tm_hour -= 12;

}

if( today->tm_hour == 0 )

today->tm_hour = 12;

printf( "12-hour time:\t\t\t\t%.8s %s\n",

asctime( today ) + 11, ampm );

_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" );

if( mktime( &xmas ) != (time_t)-1 )

printf( "Christmas\t\t\t\t%s\n", asctime( &xmas ) );

today = localtime( &ltime );

strftime( tmpbuf, 128,

"Today is %A, day %d of %B in the year %Y.\n", today );

printf( tmpbuf );

}

Output

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.