c++ - 如何在 VIsual Studio C++ 2008 中使用本地时间函数

Question

我收到此错误:“tim.exe 中 0x00411690 处未处理的异常:0xC0000005:访问冲突读取位置 0x00000008”，当我执行已成功编译和链接的程序时，问题是 localtime() 函数不正确被 Visual C++ 2008 识别。(使用 VC++6，这个程序工作正常)。

...
int gettimeofday(struct timeval *tv, struct timezone *tz)
{
  FILETIME ft;
  unsigned __int64 tmpres = 0;
  static int tzflag = 0;

  if (NULL != tv)
  {
    GetSystemTimeAsFileTime(&ft);

    tmpres |= ft.dwHighDateTime;
    tmpres <<= 32;
    tmpres |= ft.dwLowDateTime;

    tmpres /= 10;  /*convert into microseconds*/
    /*converting file time to unix epoch*/
    tmpres -= DELTA_EPOCH_IN_MICROSECS; 
    tv->tv_sec = (long)(tmpres / 1000000UL);
    tv->tv_usec = (long)(tmpres % 1000000UL);
  }

  if (NULL != tz)
  {
    if (!tzflag)
    {
      _tzset();
      tzflag++;
    }
    tz->tz_minuteswest = _timezone / 60;
    tz->tz_dsttime = _daylight;
  }

  return 0;
}
uint32_t stampstart() 
{ 
 struct timeval  tv; 
 struct timezone tz; 
 struct tm      *tm; 
 uint32_t         start; 

 gettimeofday(&tv, &tz); 
 tm = localtime(&tv.tv_sec);  /////--- problem is here --- 

 printf("TIMESTAMP-START\t  %d:%02d:%02d:%d (~%d ms)\n", tm->tm_hour, 
        tm->tm_min, tm->tm_sec, tv.tv_usec, 
        tm->tm_hour * 3600 * 1000 + tm->tm_min * 60 * 1000 + 
        tm->tm_sec * 1000 + tv.tv_usec / 1000);  

 start = tm->tm_hour * 3600 * 1000 + tm->tm_min * 60 * 1000 + 
  tm->tm_sec * 1000 + tv.tv_usec / 1000; 

 return (start); 

} 

有什么想法，谢谢回复:

Answer 1

documentation说:

Return a pointer to the structure result. If the value in timer represents a date before midnight, January 1, 1970, return NULL.

因此，请验证您发送的时间值是否正确。好像有点吓人。