objective-c 如何获取 iPhone 中的时差
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How to Get time difference in iPhone
提问by New to iPhone
I have 2 arrays with time values in it. They are in the following format. mm:ss:hundreds of a sec. I want to get the difference between the two [lastObjects] in the arrays. NSDate is not working because the last value is in hundredsth of a sec.
我有 2 个带有时间值的数组。它们采用以下格式。mm:ss:数百秒。我想获得数组中两个 [lastObjects] 之间的差异。NSDate 不起作用，因为最后一个值是百分之一秒。
A question. If the second date is larger than the first will it give me a negative number like -01:10:00 ?
一个问题。如果第二个日期大于第一个日期，它会给我一个像 -01:10:00 这样的负数吗？
回答by Nathan de Vries
Your problem has two parts, parsing the time and getting the difference:
您的问题有两个部分，解析时间并获取差异：
NSDateFormatter* dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"] autorelease]];
[dateFormatter setDateFormat:@"mm:ss:SS"];
NSDate* firstDate = [dateFormatter dateFromString:@"01:00:00"];
NSDate* secondDate = [dateFormatter dateFromString:@"01:02:00"];
NSTimeInterval timeDifference = [secondDate timeIntervalSinceDate:firstDate];
回答by Daniel
NSDateshould work for you, use timeIntervalSinceDate:, which returns a time interval which has millisecond precision.
NSDate应该对你有用，使用timeIntervalSinceDate:，它返回一个具有毫秒精度的时间间隔。
