考虑区域设置等的一些NSDate问题

1 回答

• 2

  NSWeekdayCalendarUnit：总是1周日和7周六？无论设置什么语言环境？

  那是正确的 . 但这并不意味着1 =星期天总是被认为是本周的第一天 . NSCalendar 有一个 firstWeekDay 方法，这是依赖于语言环境的 . （例如，在德国，星期一是一周的第一天 . ）

  如果我NSLog我的endDate（如下面的代码）或开始日期，它通常是日期和23:00:00，因为我住在GMT 1时区 . 这是正确的吗？

  那是正确的 .

  这个功能一般是否正常，或者我会遇到一些问题，具体取决于具体的区域设置？

  你的方法看起来过于复杂 . 确定您可以使用的时间段

  NSDate *now = [NSDate date];
  NSCalendar *cal = [NSCalendar currentCalendar];
  NSDate *startOfPeriod, *endOfPeriod;
  NSTimeInterval lengthOfPeriod;
  
  NSCalendarUnit unit = NSDayCalendarUnit; // or NSWeekCalendarUnit, NSMonthCalendarUnit, ...
  [cal rangeOfUnit:unit startDate:&startOfPeriod interval:&lengthOfPeriod forDate:now];
  endOfPeriod = [startOfPeriod dateByAddingTimeInterval:lengthOfPeriod]
  

  这应该根据您的语言环境正常工作 . 今天（德国，2月16日，星期日）的当前一周将给出结果

  startOfPeriod =  2014-02-10 00:00:00 CET
  endOfPeriod   =  2014-02-17 00:00:00 CET
  

  因为这周从星期一开始 . （所以实际上 endOfPeriod 不是期末，而是下一期的开始 . ）

  对于 semi-annual period ，没有相应的 NSCalendarUnit ，因此您可以按以下步骤操作：

  NSDate *now = [NSDate date];
  NSCalendar *cal = [NSCalendar currentCalendar];
  
  // Compute start and end of the current year (as above):
  NSDate *startOfYear, *endOfYear;
  NSTimeInterval lengthOfYear;
  NSCalendarUnit unit = NSYearCalendarUnit;
  [cal rangeOfUnit:unit startDate:&startOfYear interval:&lengthOfYear forDate:now];
  endOfYear = [startOfYear dateByAddingTimeInterval:lengthOfYear];
  
  // Compute middle of the year:
  NSDateComponents *halfYear = [[NSDateComponents alloc] init];
  NSRange range = [cal rangeOfUnit:NSMonthCalendarUnit inUnit:NSYearCalendarUnit forDate:now];
  halfYear.month = range.length/2;
  NSDate *middleOfYear = [cal dateByAddingComponents:halfYear toDate:startOfYear options:0];
  
  // Compare current date with middle of the year and set start/end of period:
  NSDate *startOfPeriod, *endOfPeriod;
  if ([now compare:middleOfYear] == NSOrderedAscending) {
      startOfPeriod = startOfYear;
      endOfPeriod = middleOfYear;
  } else {
      startOfPeriod = middleOfYear;
      endOfPeriod = endOfYear;
  }
  

  EDIT: Changed everything with the help from Martin to this. Works, but still confused about the end date +1day +1 hour necessity...

  + (NSDate *)startDateForCostPeriod:(CostPeriod)costPeriod withDate:(NSDate *)date
  {
      NSCalendar *calender = [NSCalendar currentCalendar];
      NSDate *startOfPeriod;
      NSTimeInterval lengthOfPeriod;
      //If unit is not initialized here, semi annual throws always a caution message since no unit is initialized there
      NSCalendarUnit unit = NSMonthCalendarUnit;
  
      //For the SemiAnnual period we need date components
      NSDateComponents *todayComponents =
      [calender components:(NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit ) fromDate:date];
      NSDateComponents *startDateComponents = [[NSDateComponents alloc] init];
  
      switch (costPeriod) {
          case CostPeriodDaily:
              unit = NSDayCalendarUnit;
              break;
  
          case CostPeriodWeekly:
              unit = NSWeekCalendarUnit;
              break;
  
          case CostPeriodMonthly:
              unit = NSMonthCalendarUnit;
              break;
  
          case CostPeriodSemiAnnually:
              [startDateComponents setDay:1];
              [startDateComponents setYear:[todayComponents year]];
  
              if([todayComponents month] <= 6){
                  [startDateComponents setMonth:1];
              } else {
                  [startDateComponents setMonth:7];
              }
              break;
  
          case CostPeriodAnnually:
              unit = NSYearCalendarUnit;
              break;
  
          default:
              unit = NSMonthCalendarUnit;
              break;
      }
  
      if(costPeriod != CostPeriodSemiAnnually){
          [calender rangeOfUnit:unit startDate:&startOfPeriod interval:&lengthOfPeriod forDate:date];
          return startOfPeriod;
      } else {
          return [calender dateFromComponents:startDateComponents];
      }
  }
  
  + (NSDate *)endDateForCostPeriod:(CostPeriod)costPeriod withDate:(NSDate *)date
  {
      NSCalendar *calender = [NSCalendar currentCalendar];
      NSDate *startOfPeriod;
      NSTimeInterval lengthOfPeriod;
      //If unit is not initialized here, semi annual throws always a caution message since no unit is initialized there
      NSCalendarUnit unit = NSMonthCalendarUnit;
  
      //For the SemiAnnual period we need date components
      NSDateComponents *todayComponents =
      [calender components:(NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit ) fromDate:date];
      NSDateComponents *endDateComponents = [[NSDateComponents alloc] init];
  
      switch (costPeriod) {
          case CostPeriodDaily:
              unit = NSDayCalendarUnit;
              break;
  
          case CostPeriodWeekly:
              unit = NSWeekCalendarUnit;
              break;
  
          case CostPeriodMonthly:
              unit = NSMonthCalendarUnit;
              break;
  
          case CostPeriodSemiAnnually:
              [endDateComponents setYear:[todayComponents year]];
  
              if([todayComponents month] <= 6){
                  [endDateComponents setDay:30];
                  [endDateComponents setMonth:6];
              } else {
                  [endDateComponents setDay:31];
                  [endDateComponents setMonth:12];
              }
              break;
  
          case CostPeriodAnnually:
              unit = NSYearCalendarUnit;
              break;
  
          default:
              unit = NSMonthCalendarUnit;
              break;
      }
  
      if(costPeriod != CostPeriodSemiAnnually){
          [calender rangeOfUnit:unit startDate:&startOfPeriod interval:&lengthOfPeriod forDate:date];
          return [startOfPeriod dateByAddingTimeInterval:lengthOfPeriod];
      } else {
          //somehow if you take the date without a time it is always 1 day and 1 hour before. i.e. 16.2.2014 is 15.2.2014 22:00:00
          //thats why you need to add 1 day and 1 hour!
          NSDate *endDate = [calender dateFromComponents:endDateComponents];
          NSDateComponents *componentsToAdd = [[NSDateComponents alloc] init];
          [componentsToAdd setDay: 1];
          [componentsToAdd setHour: 1];
          endDate = [calender dateByAddingComponents:componentsToAdd
                                               toDate:endDate options:0];
  
          return endDate;
      }
  }
  

  回复于 2024-04-29T08:17:29+08:00