NSDateFormatter在特定日期返回null [英] NSDateFormatter returns null for specific dates

问题描述

NSDateFormatter 遇到问题。在某些特定日期返回 null 。

I'm having a problem with the NSDateFormatter. It is returning null for some specific dates.

我执行此功能来调试该情况：

I did this function to debug the case:

- (void) debugTest:(NSString *)dateStr{

    NSLog(@"String: %@", dateStr);

    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    [df setDateFormat:@"yyyy-MM-dd"];

    NSDate *dateObj = [df dateFromString: dateStr];

    NSLog(@"Date: %@", dateObj);

}

这是某些日期的日志输出：

This is my log output for some dates:

String: 2012-10-18
Date: 2012-10-18 03:00:00 +0000
String: 2012-10-19
Date: 2012-10-19 03:00:00 +0000
String: 2012-10-20
Date: 2012-10-20 03:00:00 +0000
String: 2012-10-21
Date: (null)
String: 2012-10-22
Date: 2012-10-22 02:00:00 +0000
String: 2012-10-23
Date: 2012-10-23 02:00:00 +0000

为什么仅在 2012-10-21 日期返回null？

Why it is returning null only for the date 2012-10-21?

我以 2011-10-01至2014-11-01 的间隔进行了其他测试，以下日期返回 null ：

I did other tests with the interval from 2011-10-01 to 2014-11-01 and the following dates returned null:

2011-10-16, 2012-10-21, 2013-10-20, 2014-10-19

这是某种错误吗？我做错了吗？

Is this some kind of bug? I am doing something wrong?

推荐答案

我将回答我自己的问题，只是为了注册，以防有人遇到相同的问题：

I will answer my own question just to register in case of someone get the same problem:

我已添加到日期格式化程序
[df setLocale：[[NSLocale alloc] initWithLocaleIdentifier：@ en_US_POSIX]]]； code>和 [df setTimeZone：[NSTimeZone timeZoneWithName：@ GMT]]; 。

I added to my date formatter [df setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]]; AND [df setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];.

所以，我的新代码是：

- (void) debugTest:(NSString *)dateStr{

    NSLog(@"String: %@", dateStr);

    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    [df setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
    [df setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];
    [df setDateFormat:@"yyyy-MM-dd"];

    NSDate *dateObj = [df dateFromString: dateStr];

    NSLog(@"Date: %@", dateObj);

}

我认为问题与设备的配置有关，设置这两个属性解决了这个问题。

I think the problem was related to the device's configuration, setting the two properties fixed the problem.

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