C++时间标准库时间time和系统时间的使用

C++时间标准库时间time和系统时间的使用

 

1. C++标准库中的时间需要引用time.h，可以取的本地时间或者格林威治时间，只能精确到秒

 

#include <iostream>

/*包含time头文件*/
#include <time.h>


using  namespace  std;

int  main()
{
    //time_t是long类型，精确到秒，是当前时间和1970年1月1日零点时间的差
    const  time_t  t = time (NULL);

    cout<< "current time is " <<t<<endl;

    /*本地时间：日期，时间 年月日，星期，时分秒*/
    struct  tm * current_time = localtime (&t);
    printf ( "current year is %d;current month is %d;current date of month is %d\r\n" ,
        1900 + current_time->tm_year,
        1 + current_time->tm_mon /*此month的范围为0-11*/ ,
        current_time->tm_mday);

    printf ( "current day of year is %d;current day in week is %d\r\n" ,
        current_time->tm_yday, /*当前日期是今年的第多少天[0,365] */
        current_time->tm_wday /*days since Sunday - [0,6] */ );

    printf ( "time part %d:%d:%d \r\n" ,
        current_time->tm_hour,
        current_time->tm_min,
        current_time->tm_sec);

    printf ( "\t本地时间：%d-%d-%d %d:%d:%d\r\n" ,
        current_time->tm_year + 1900,
        current_time->tm_mon + 1,
        current_time->tm_mday,
        current_time->tm_hour,
        current_time->tm_min,
        current_time->tm_sec);

    /*格林威治时间*/
    struct  tm * current_gmtime = gmtime (&t);

    printf ( "格林威治时间：%d-%d-%d %d:%d:%d\r\n" ,
        current_gmtime->tm_year + 1900,
        current_gmtime->tm_mon + 1,
        current_gmtime->tm_mday,
        current_gmtime->tm_hour,
        current_gmtime->tm_min,
        current_gmtime->tm_sec);


    system ( "pause" );
    return  0;
}

 

2. 系统时间 SYSTEMTIME 使用时要引用windows.h，可以精确到毫秒级别

 

#include <iostream>
#include <Windows.h>


int  main(){
    //声明变量
    SYSTEMTIME sys_time;

    //将变量值设置为本地时间
    GetLocalTime( &sys_time );

    //输出时间
    printf ( "%4d/%02d/%02d %02d:%02d:%02d.%03d 星期%1d\n" ,sys_time.wYear,
        sys_time.wMonth,
        sys_time.wDay,
        sys_time.wHour,
        sys_time.wMinute,
        sys_time.wSecond,
        sys_time.wMilliseconds,
        sys_time.wDayOfWeek);

    system ( "time" );

    system ( "pause" );
    return  0;
}