Question

我正试图绕过一个日期验证，拒绝接受明天之前的任何事情到目前为止，我有这个：

NSDate *dateY = [NSDate dateWithTimeIntervalSinceNow:-86400];
                // Negative one day, in seconds (-60*60*24)
NSLog(@"%@", [NSDate date]);
    // "yyyy-MM-dd HH:mm:ss Z", accurate assuming Z = +0000
NSLog(@"%@", dateY);
    // "yyyy-MM-dd HH:mm:ss Z", same accuracy (minus one day)

这很好，但dateY不是NSNumber。我需要一个NSNumber进行比较，但我找不到任何有用的东西。（我甚至不知道NSNumber如何2011-04-14 13:22:29 +0000，无论如何......）

我可以使用NSDateFormatter将NSDate转换为NSString，因此如果可以获取该字符串并将其转换为所需的NSNumber（如反对直接将NSDate转换为NSNumber，我似乎无法找到帮助，这样就可以了。

- (BOOL)validateDueDate:(id *)ioValue error:(NSError **)outError {
    NSDate *dateY = [NSDate dateWithTimeIntervalSinceNow:-86400];
    NSNumber *tis1970 = [NSNumber numberWithDouble:[dateY timeIntervalSince1970]];
    NSLog(@"NSNumber From Date : %@", tis1970);
    NSLog(@"Date From NSNumber : %@", [NSDate dateWithTimeIntervalSince1970:[tis1970 doubleValue]]);

    // Due dates in the past are not valid
    // Enforced that a due date has to be >= today's date
    if ([*ioValue compare:[NSDate date]] == NSOrderedAscending) {
        if (outError != NULL) {
            NSString *errorStr = [[[NSString alloc] initWithString:@"Due date must be today or later."] autorelease];
            NSDictionary *userInfoDictionary = [NSDictionary dictionaryWithObject:errorStr forKey:@"ErrorString"];
            NSError *error = [[[NSError alloc]
                                initWithDomain:TASKS_ERROR_DOMAIN
                                code:DUEDATE_VALIDATION_ERROR_CODE
                                userInfo:userInfoDictionary] autorelease];
            *outError = error;
            }
        return NO;
    } else {
        return YES;
    }
}

目前，用户不允许在明天之前选择日期。 errorStr谎言。在今天比以前更有意义作为拒绝保存日期的规则，所以我一直在与这个事情作斗争，让我昨天用它代替今天，而不是看得更深。

编辑：使用NSOrderedSame可以选择任何日期而不会出现错误。那不行。

Answer 1

您可以将NSDate转换为NSNumber，如下所示：

NSDate *aDate = [NSDate date];
NSNumber *secondsSinceRefDate = [NSNumber numberWithDouble:[aDate timeIntervalSinceReferenceDate]];

并转换回来：

aDate = [NSDate dateWithTimeIntervalSinceReferenceDate:[NSNumber doubleValue]];

Answer 2

获得NSNumber所需的只是

NSDate *dateY = [NSDate dateWithTimeIntervalSinceNow:-86400];
NSNumber *tis1970 = [NSNumber numberWithDouble:[dateY timeIntervalSince1970]];
NSLog(@"NSNumber From Date : %@", tis1970);
NSLog(@"Date From NSNumber : %@", [NSDate dateWithTimeIntervalSince1970:[tis1970 doubleValue]]);

Answer 3

您永远不应该使用86400来计算日期差异，因为并非所有日子都有86,400秒。请改用NSDateComponents：

- (BOOL)validateDueDate:(NSDate *)dueDate error:(NSError *)error {
  NSDate *today = [NSDate date];
  NSCalendar *calendar = [NSCalendar currentCalendar];
  NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:today];
  //adjust the components to tomorrow at the first instant of the day
  [components setDay:[components day] + 1];
  [components setHour:0];
  [components setMinute:0];
  [components setSecond:0];
  NSDate *tomorrow = [calendar dateFromComponents:components];

  NSDate *earlierDate = [dueDate earlierDate:tomorrow];
  if ([earlierDate isEqualToDate:dueDate]) {
    //the dueDate is before tomorrow
    if (error != nil) {
      NSString *errorStr = [[[NSString alloc] initWithString:@"Due date must be today or later."] autorelease];
      NSDictionary *userInfoDictionary = [NSDictionary dictionaryWithObject:errorStr forKey:NSLocalizedDescriptionKey];
      *error = [[[NSError alloc] initWithDomain:TASKS_ERROR_DOMAIN code:DUEDATE_VALIDATION_ERROR_CODE userInfo:userInfoDictionary] autorelease];
    }
    return NO;
  }
  return YES;
}

_{警告：在浏览器中输入的代码。警告实施者}

来自NSDate的NSNumber

3 个答案: