为什么无法使用NSDateFormatter正确解析此日期字符串？ [英] Why can't I correctly parse this date string with NSDateFormatter?

问题描述

我试图解析一个由NSDateFormatter使用另一个具有相同格式的NSDateFormatter生成的字符串。

而不是试图使上一句有意义，这里有一些代码：

  NSDateFormatter * format = [[NSDateFormatter alloc] init]; 
 [format setDateFormat：@MMM dd，YYYY HH：mm]; 
 
 NSDate * now = [[NSDate alloc] init]; 
 
 NSString * dateString = [format stringFromDate：now]; 
 
 NSDateFormatter * inFormat = [[NSDateFormatter alloc] init]; 
 [inFormat setDateFormat：@MMM dd，YYYY HH：mm]; 
 
 NSDate * parsed = [inFormat dateFromString：dateString]; 
 
 NSLog（@\\\

now：|％@ | \\\

dateString：|％@ | \\\

 parsed：|％@ |，now，dateString，parsed）; 
  

当我运行此代码时，我希望日期现在，但我得到以下输出：

 
现在：| 2009-05-04 18： 23:35 -0400 | 
 dateString：| 2009年5月4日18：23 | 
 parsed：| 2008-12-21 18:23:00 -0500 |任何人都有任何想法为什么会发生这种情况？
解决方案   / div> 
您的问题是YYYY不是有效的ICU日期格式选项。 
 
 
 
资本Y仅在使用周年周期选项（即'周'w'为'Y' ）。
 
I'm trying to parse a string that was generated by an NSDateFormatter using another NSDateFormatter with the same format.

Rather than trying to make that previous sentence make sense, here's some code:
NSDateFormatter *format = [[NSDateFormatter alloc] init];
[format setDateFormat:@"MMM dd, YYYY HH:mm"];

NSDate *now = [[NSDate alloc] init];

NSString *dateString = [format stringFromDate:now];

NSDateFormatter *inFormat = [[NSDateFormatter alloc] init];
[inFormat setDateFormat:@"MMM dd, YYYY HH:mm"];

NSDate *parsed = [inFormat dateFromString:dateString];

NSLog(@"\n"
      "now:        |%@| \n"
      "dateString: |%@| \n"
      "parsed:     |%@|", now, dateString, parsed);
When I run this code, I expect that parsed would contain the same date as now but instead I get the following output:
now:        |2009-05-04 18:23:35 -0400| 
dateString: |May 04, 2009 18:23| 
parsed:     |2008-12-21 18:23:00 -0500|
Anybody have any ideas why this is happening?
解决方案
Your problem is that "YYYY" isn't a valid ICU date formatting option. You want "yyyy".

Capital 'Y' is only valid when used with the "week of year" option (i.e. "'Week 'w' of 'Y").

                        
这篇关于为什么无法使用NSDateFormatter正确解析此日期字符串？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！