iPhone NSDateComponent 日期错误 1.1.2011？

Question

我用“DateFromComponents”设置了一个日期，当我读出它时......它是错误的。我必须将日期设置为第二天或以后的任何时间，这样我才能得到正确的年份？!？我设置了 2011 年，当我读出它时，我得到了 2010 年!!

<小时/>

 day = 1;
 month = 1;
 year = 2011;
 NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
 NSDateComponents *components = [[NSDateComponents alloc] init];
 [components setDay:day];
 [components setMonth:month];
 [components setYear:year];
 NSDate *date = [gregorian dateFromComponents:components]; 
 [gregorian release];


 NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease]; 
 [dateFormatter setDateFormat:@"DD MMMM YYYY"];
 NSLog (@"hmm: %@",[dateFormatter stringFromDate:actDate]);

-------- 这里我得到1 一月 2010///2010 而不是 2011 !?!?

如何解决这个问题。

谢谢克里斯

Answer 1

我运行了这段代码:

NSInteger day = 1;
NSInteger month = 1;
NSInteger year =0;
NSCalendar *gregorian;
NSDateComponents *components;
NSDate *theDate;
NSDateFormatter *dateFormatter;
for (int i=2005; i<2015; i++) {
     year= i;
    gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    components = [[NSDateComponents alloc] init];
    [components setDay:day];
    [components setMonth:month];
    [components setYear:year];
    theDate = [gregorian dateFromComponents:components]; 
    [gregorian release];


    dateFormatter = [[[NSDateFormatter alloc] init] autorelease]; 
    [dateFormatter setDateFormat:@"DD MMMM YYYY"];
    NSLog(@"year=%d",year);
    NSLog (@"hmm: %@",[dateFormatter stringFromDate:theDate]);
    NSLog(@"theDate=%@\n\n",theDate);
}

...并得到以下输出:

 year=2005
 hmm: 01 January 2004
 theDate=2005-01-01 00:00:00 -0600

 year=2006
 hmm: 01 January 2006
 theDate=2006-01-01 00:00:00 -0600

 year=2007
 hmm: 01 January 2007
 theDate=2007-01-01 00:00:00 -0600

 year=2008
 hmm: 01 January 2008
 theDate=2008-01-01 00:00:00 -0600

 year=2009
 hmm: 01 January 2008
 theDate=2009-01-01 00:00:00 -0600

 year=2010
 hmm: 01 January 2009
 theDate=2010-01-01 00:00:00 -0600

 year=2011
 hmm: 01 January 2010
 theDate=2011-01-01 00:00:00 -0600

 year=2012
 hmm: 01 January 2012
 theDate=2012-01-01 00:00:00 -0600

 year=2013
 hmm: 01 January 2013
 theDate=2013-01-01 00:00:00 -0600

 year=2014
 hmm: 01 January 2014
 theDate=2014-01-01 00:00:00 -0600

显然问题出在格式化程序而不是日期。但是，我不知道格式化程序有什么问题。 。

编辑:

转移:

[dateFormatter setDateFormat:@"DD MMMM YYYY"];

...至:

[dateFormatter setDateFormat:@"DD MMMM yyyy"];

...解决了问题，尽管我不知道为什么。