ios - 某些日期的 NSDateformatter 问题

Question

我的代码是

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"EDT"]];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:dd"];
    NSString *strDate = @"my date from backend";
    NSLog(@"value from backend %@",strDate);
    NSLog(@"after chnage by formatter %@",[dateFormatter dateFromString:strDate]);

在我的控制台记录结果

value from backend 2014-04-18 05:01:13
after chnage by formatter 2014-04-12 23:31:00 +0000
value from backend 2014-04-18 05:01:34
after chnage by formatter (null)
value from backend 2014-04-18 05:04:27
after chnage by formatter 2014-04-26 23:34:00 +0000
value from backend 2014-04-18 05:04:47
after chnage by formatter (null)
value from backend 2014-04-18 05:05:14
after chnage by formatter 2014-04-13 23:35:00 +0000
value from backend 2014-04-18 05:05:21
after chnage by formatter 2014-04-20 23:35:00 +0000
value from backend 2014-04-18 05:08:38
after chnage by formatter (null)

为什么有些日期是空的..任何人都可以帮助我吗？

Answer 1

日期格式应该是:

[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

请注意，我将末尾的 dd 更改为 ss。 对于大多数情况，返回的日期是错误的。对于那些秒数超过 30 的情况，您将得到 null。