timeIntervalSinceDate 报告错误值

Question

我有两个通过按下按钮设置的日期。这些存储在继承自 NSObject 的自定义对象中。

属性：

@property (nonatomic, strong) NSDate *firstDate;
@property (nonatomic, strong) NSDate *secondDate;

自定义getter和setter方法：

- (void)setFirstDate:(float)firstDate {
    _firstDate = [self dateByOmittingSeconds:firstDate];
}

- (void)setSecondDate:(float)secondDate {
    _secondDate = [self dateByOmittingSeconds:secondDate];
}

- (NSDate *)firstDate {
    return [self dateByOmittingSeconds:_firstDate];
}

- (NSDate *)secondDate {
    return [self dateByOmittingSeconds:_secondDate];
}

删除 NSDate 的秒部分的函数：

-(NSDate *)dateByOmittingSeconds:(NSDate *)date
{
// Setup an NSCalendar
NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier: NSCalendarIdentifierGregorian];

// Setup NSDateComponents
NSDateComponents *components = [gregorianCalendar components: NSUIntegerMax fromDate: date];

// Set the seconds
[components setSecond:00];

return [gregorianCalendar dateFromComponents: components];
}

第一个日期是08:00，第二个日期是13:00，都定在今天。

我正在获取两个日期之间的距离并将它们格式化为：

NSString *myString = [self timeFormatted:[currentModel.secondDate timeIntervalSinceDate:currentModel.firstDate]];


- (NSString *)timeFormatted:(int)totalSeconds
{

// int seconds = totalSeconds % 60;
int minutes = (totalSeconds / 60) % 60;
int hours = totalSeconds / 3600;

return [NSString stringWithFormat:@"%luh %lum", (unsigned long)hours, (unsigned long)minutes];
}

但它报告 4h 59m, 17999.254732 秒.

有人知道这是为什么吗？

谢谢！

Answer 1

问题不在于timeIntervalSinceDate，而在于你的 dateByOmittingSeconds 未正确截断的方法秒。原因是second不是NSDateComponents中的最小单位。还有 nanosecond，如果您也将它设置为零

[components setSecond:0];
[components setNanosecond:0];

然后它将按预期工作。

一个稍微简单的解决方案是使用 rangeOfUnit:

-(NSDate *)dateByOmittingSeconds:(NSDate *)date
{
    NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier: NSCalendarIdentifierGregorian];
    NSDate *result;
    [gregorianCalendar rangeOfUnit:NSCalendarUnitSecond startDate:&result interval:nil forDate:date];
    return result;
}

timeIntervalSinceDate 报告错误值

timeIntervalSinceDate reporting wrong value

objective-c

nsdate

nstimeinterval

ios