iOS计算上次日期距离现在多久的代码

/** * 计算上次日期距离现在多久 * * @param lastTime  上次日期(需要和格式对应) * @param format1   上次日期格式 * @param currentTime 最近日期(需要和格式对应) * @param format2   最近日期格式 * * @return xx分钟前、xx小时前、xx天前 */+ (NSString *)timeIntervalFromLastTime:(NSString *)lastTime            lastTimeFormat:(NSString *)format1             ToCurrentTime:(NSString *)currentTime           currentTimeFormat:(NSString *)format2{  //上次时间  NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc]init];  dateFormatter1.dateFormat = format1;  NSDate *lastDate = [dateFormatter1 dateFromString:lastTime];  //当前时间  NSDateFormatter *dateFormatter2 = [[NSDateFormatter alloc]init];  dateFormatter2.dateFormat = format2;  NSDate *currentDate = [dateFormatter2 dateFromString:currentTime];  return [Utilities timeIntervalFromLastTime:lastDate ToCurrentTime:currentDate];} + (NSString *)timeIntervalFromLastTime:(NSDate *)lastTime ToCurrentTime:(NSDate *)currentTime{  NSTimeZone *timeZone = [NSTimeZone systemTimeZone];  //上次时间  NSDate *lastDate = [lastTime dateByAddingTimeInterval:[timeZone secondsFromGMTForDate:lastTime]];  //当前时间  NSDate *currentDate = [currentTime dateByAddingTimeInterval:[timeZone secondsFromGMTForDate:currentTime]];  //时间间隔  NSInteger intevalTime = [currentDate timeIntervalSinceReferenceDate] - [lastDate timeIntervalSinceReferenceDate];   //秒、分、小时、天、月、年  NSInteger minutes = intevalTime / 60;  NSInteger hours = intevalTime / 60 / 60;  NSInteger day = intevalTime / 60 / 60 / 24;  NSInteger month = intevalTime / 60 / 60 / 24 / 30;  NSInteger yers = intevalTime / 60 / 60 / 24 / 365;   if (minutes <= 10) {    return @"刚刚";  }else if (minutes < 60){    return [NSString stringWithFormat: @"%ld分钟前",(long)minutes];  }else if (hours < 24){    return [NSString stringWithFormat: @"%ld小时前",(long)hours];  }else if (day < 30){    return [NSString stringWithFormat: @"%ld天前",(long)day];  }else if (month < 12){    NSDateFormatter * df =[[NSDateFormatter alloc]init];    df.dateFormat = @"M月d日";    NSString * time = [df stringFromDate:lastDate];    return time;  }else if (yers >= 1){    NSDateFormatter * df =[[NSDateFormatter alloc]init];    df.dateFormat = @"yyyy年M月d日";    NSString * time = [df stringFromDate:lastDate];    return time;  }  return @"";} 

NSLog(@"/n/nresult: %@", [Utilities timeIntervalFromLastTime:@"2015年12月8日 15:50"                      lastTimeFormat:@"yyyy年MM月dd日 HH:mm"                      ToCurrentTime:@"2015/12/08 16:12"                    currentTimeFormat:@"yyyy/MM/dd HH:mm"]);