Question

参考预先回答的问题：Getting first and last days of current week

以上链接有两个答案。其中一个是理论上的，另一个是PyObjC（Python-Objective C桥接语言），快速谷歌搜索确认PyObjC不适用于iPhone SDK。

关于这个问题，如何将PyObjC代码翻译成与iPhone SDK兼容。

目标：假设今天（星期二）是19日，太阳。是第17次（周开始）和周六。 23日是周末。我希望得到像19/01 - 23/01这样的字符串[即周开始（炒作）周末]

Answer 1

如果您有NSDate，则可以使用当前NSCalendar来检索该日期的NSDateComponents。将NSDateComponents的{{1}}设置为1（一周的第一天），创建副本，并将副本的weekday设置为7（一周的最后一天）。然后使用weekday将NSCalendar转换回各自的NSDateComponents对象，之后您可以使用NSDate创建字符串表示形式。

此链接有一个关于如何获取日期工作日的示例：https://stackoverflow.com/questions/1057349#1057405

Answer 2

以下是一些代码，它还会检查上周开始的一个边缘情况：

// Finds the date for the first day of the week
- (NSDate *)getFirstDayOfTheWeekFromDate:(NSDate *)givenDate
{
    NSCalendar *calendar = [NSCalendar currentCalendar];

    // Edge case where beginning of week starts in the prior month
    NSDateComponents *edgeCase = [[NSDateComponents alloc] init];
    [edgeCase setMonth:2];
    [edgeCase setDay:1];
    [edgeCase setYear:2013];
    NSDate *edgeCaseDate = [calendar dateFromComponents:edgeCase];

    NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:edgeCaseDate];
    [components setWeekday:1]; // 1 == Sunday, 7 == Saturday
    [components setWeek:[components week]];

    NSLog(@"Edge case date is %@ and beginning of that week is %@", edgeCaseDate , [calendar dateFromComponents:components]);

    // Find Sunday for the given date
    components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:givenDate];
    [components setWeekday:1]; // 1 == Sunday, 7 == Saturday
    [components setWeek:[components week]];

    NSLog(@"Original date is %@ and beginning of week is %@", givenDate , [calendar dateFromComponents:components]);

    return [calendar dateFromComponents:components];
}

编辑：上面的相关代码

- (NSDate *)firstDayOfWeekFrom:(NSDate *)givenDate {
  NSCalendar *calendar = [NSCalendar currentCalendar];

  NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:givenDate];
  [components setWeekday:1]; // 1 == Sunday, 7 == Saturday
  [components setWeekOfYear:[components weekOfYear]];

  return [calendar dateFromComponents:components];
}

Answer 3

这是我几天前找到的，终于找到了。 rangeOfUnit:startDate:interval:forDate:中有一种方法NSDate，并以简单的方式执行此操作。你可以在： Current Week Start and End Date

Answer 4

NSDate *weekDate = [NSDate date];
NSCalendar *myCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

NSDateComponents *currentComps = [myCalendar components:( NSYearCalendarUnit | NSMonthCalendarUnit | NSWeekOfYearCalendarUnit | NSWeekdayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit) fromDate:weekDate];
int ff = currentComps.weekOfYear;
NSLog(@"1  %d", ff);

[currentComps setWeekday:1]; // 1: sunday
NSDate *firstDayOfTheWeek = [myCalendar dateFromComponents:currentComps];
[currentComps setWeekday:7]; // 7: saturday
NSDate *lastDayOfTheWeek = [myCalendar dateFromComponents:currentComps];

NSDateFormatter *myDateFormatter = [[NSDateFormatter alloc] init];
myDateFormatter.dateFormat = @"dd EEEE";
NSString *firstStr = [myDateFormatter stringFromDate:firstDayOfTheWeek];
NSString *secondStr = [myDateFormatter stringFromDate:lastDayOfTheWeek];

NSLog(@"first - %@ \nlast - %@", firstStr, secondStr);

计算当前周的第一天和最后一天

4 个答案: