Objective c 为什么我计算的时间戳不准确（+；32或+；16秒）？

我无法理解代码的结果，我需要你的帮助

例如，如果当前时间是凌晨5点，我想在调用我的方法时得到两个时间戳：

[self getPeriodValues:@"day"];

[self getPeriodValues:@"year"];

• 当日00时00分的时间戳
• 当前时间上午5点的时间戳

对于第一个时间戳，我有结果，但还有32秒

在我的第二个示例中，如果当前日期是2011/12/30上午5点，并且我在调用我的方法时需要两个时间戳：

[self getPeriodValues:@"day"];

[self getPeriodValues:@"year"];

• 当前年份的时间戳，日期为2011/01/01，00时00分
• 当前日期和时间的时间戳：2011/12/30上午5点

对于第一个时间戳，我有结果，但还有16秒

我的所有案例：

-(void)getPeriodValues:(NSString*)period
{
log_debug("@@@@@ BackEnd - getPeriodValues @@@@@")

float startDateFloatTimeStamp;
float endDateFloatTimeStamp;

NSString * startDateStrNumericTimeStamp;
NSString * endDateStrNumericTimeStamp;

NSDateComponents *compsStart;
NSDateComponents *compsEnd;

NSDate * startDate;
NSDate * endDate;

NSCalendar *calendar = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit| NSWeekCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDate *date = [NSDate date];
NSDateComponents *dateComponents = [calendar components:unitFlags fromDate:date] ;
NSInteger year = [dateComponents year];
NSInteger month = [dateComponents month];
//NSInteger week = [dateComponents week];
NSInteger day = [dateComponents day];
NSInteger hour = [dateComponents hour];
NSInteger minute = [dateComponents minute];
NSInteger second = [dateComponents second];

log_debug (@"year : %ld", (long)year);
log_debug (@"month : %ld", (long)month);
log_debug (@"day : %ld", (long)day);
log_debug (@"hour : %ld", (long)hour);
log_debug (@"minute : %ld", (long)minute);
log_debug (@"second : %ld", (long)second);
log_debug (@"date : %ld", (long)[date timeIntervalSince1970]);

if ([period isEqualToString:@"day"]) {

    // start at 00h00m32s of current day to current time

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day];



    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];


} else if ([period isEqualToString:@"yesterday"]) {

    // Start yesterday at 00h00m32s, End today at 00h00m32s

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day-1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];


} else if ([period isEqualToString:@"week"]) {

    // -7 days at 00h00m32s, End today at 00h00m32s

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day-7];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];

} else if ([period isEqualToString:@"month"]) {

    // ...

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];

} else if ([period isEqualToString:@"previousMonth"]) {

    // ...

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month-1];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:1];

} else if ([period isEqualToString:@"year"]) {

    // du 01/01 de cette année à 00h00m16s, à aujourd'hui pour l'heure actuelle

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:1];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];

} else if ([period isEqualToString:@"previousYear"]) {

    // ...

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year-1];
    [compsStart setMonth:1];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:1];
    [compsEnd setDay:1];

} else {

    // ... same as day

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day];


    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];

}

startDate = [[NSCalendar currentCalendar] dateFromComponents:compsStart];
startDateFloatTimeStamp = [startDate timeIntervalSince1970];

endDate = [[NSCalendar currentCalendar] dateFromComponents:compsEnd];
endDateFloatTimeStamp = [endDate timeIntervalSince1970];

startDateStrNumericTimeStamp = [NSString stringWithFormat:@"%i000",(int) floor(startDateFloatTimeStamp)];
endDateStrNumericTimeStamp = [NSString stringWithFormat:@"%i000",(int) floor(endDateFloatTimeStamp)];

log_debug(@"Start timestamp : %@",startDateStrNumericTimeStamp);
log_debug(@"End timestamp : %@",endDateStrNumericTimeStamp);

...
}

• 对于"一天",我还有32秒
• 对于"昨天",我还有32秒
• 对于"一周",我还有32秒
• 对于"一个月",我还有32秒
• 对于"上个月",我还有32秒
• 对于"年",我还有16秒
• 对于"上一年",我还有16秒

以下是我的方法代码：

-(void)getPeriodValues:(NSString*)period
{
log_debug("@@@@@ BackEnd - getPeriodValues @@@@@")

float startDateFloatTimeStamp;
float endDateFloatTimeStamp;

NSString * startDateStrNumericTimeStamp;
NSString * endDateStrNumericTimeStamp;

NSDateComponents *compsStart;
NSDateComponents *compsEnd;

NSDate * startDate;
NSDate * endDate;

NSCalendar *calendar = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit| NSWeekCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDate *date = [NSDate date];
NSDateComponents *dateComponents = [calendar components:unitFlags fromDate:date] ;
NSInteger year = [dateComponents year];
NSInteger month = [dateComponents month];
//NSInteger week = [dateComponents week];
NSInteger day = [dateComponents day];
NSInteger hour = [dateComponents hour];
NSInteger minute = [dateComponents minute];
NSInteger second = [dateComponents second];

log_debug (@"year : %ld", (long)year);
log_debug (@"month : %ld", (long)month);
log_debug (@"day : %ld", (long)day);
log_debug (@"hour : %ld", (long)hour);
log_debug (@"minute : %ld", (long)minute);
log_debug (@"second : %ld", (long)second);
log_debug (@"date : %ld", (long)[date timeIntervalSince1970]);

if ([period isEqualToString:@"day"]) {

    // start at 00h00m32s of current day to current time

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day];



    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];


} else if ([period isEqualToString:@"yesterday"]) {

    // Start yesterday at 00h00m32s, End today at 00h00m32s

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day-1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];


} else if ([period isEqualToString:@"week"]) {

    // -7 days at 00h00m32s, End today at 00h00m32s

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day-7];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];

} else if ([period isEqualToString:@"month"]) {

    // ...

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];

} else if ([period isEqualToString:@"previousMonth"]) {

    // ...

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month-1];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:1];

} else if ([period isEqualToString:@"year"]) {

    // du 01/01 de cette année à 00h00m16s, à aujourd'hui pour l'heure actuelle

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:1];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];

} else if ([period isEqualToString:@"previousYear"]) {

    // ...

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year-1];
    [compsStart setMonth:1];
    [compsStart setDay:1];

    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:1];
    [compsEnd setDay:1];

} else {

    // ... same as day

    compsStart = [[[NSDateComponents alloc] init] autorelease];
    [compsStart setYear:year];
    [compsStart setMonth:month];
    [compsStart setDay:day];


    compsEnd = [[[NSDateComponents alloc] init] autorelease];
    [compsEnd setYear:year];
    [compsEnd setMonth:month];
    [compsEnd setDay:day];
    [compsEnd setHour:hour];
    [compsEnd setMinute:minute];
    [compsEnd setSecond:second];

}

startDate = [[NSCalendar currentCalendar] dateFromComponents:compsStart];
startDateFloatTimeStamp = [startDate timeIntervalSince1970];

endDate = [[NSCalendar currentCalendar] dateFromComponents:compsEnd];
endDateFloatTimeStamp = [endDate timeIntervalSince1970];

startDateStrNumericTimeStamp = [NSString stringWithFormat:@"%i000",(int) floor(startDateFloatTimeStamp)];
endDateStrNumericTimeStamp = [NSString stringWithFormat:@"%i000",(int) floor(endDateFloatTimeStamp)];

log_debug(@"Start timestamp : %@",startDateStrNumericTimeStamp);
log_debug(@"End timestamp : %@",endDateStrNumericTimeStamp);

...
}

最后，为什么我的方法会增加32秒或16秒？ 编辑以添加日志：

“日”案件：

---

我们可以看到，对于开始日，我有1325458816000，而我应该有：1325458800000

我编译了这个，当我在方法底部打印startDate和endDate时，我看不到任何额外的秒数。你能以单元测试的形式提供一个断言失败的小例子吗？@Gary，我为你提供了de day案例的日志。我无法复制这个，你能不能提供一个断言失败的最小可能测试案例，以便我可以复制它。