NSDate - dateFromString返回nil

时间:2015-06-17 01:43:46

标签: ios objective-c nsdate

我有super()有约会。我正在尝试将该日期转换为NSString。当我这样做时,我从NSDate获得nil。这是我的代码:

NSDate

以下是NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"dd/MM/yyyy"]; NSDate *date = [dateFormatter dateFromString:dateString]; NSLog(@"dateString = %@ date = %@", dateString, date);

的输出
  

NSLog

我做错了什么,我该如何解决?

1 个答案:

答案 0 :(得分:3)

日期格式与日期字符串不匹配。它必须是:: @" yyyy-MM-dd"

订单和其他字符需要匹配 yyyy四位数年份 MM为两位数的月份 dd为两位数的日子

请参阅:ICU Formatting Dates and Times

注意:DECLARE @t TABLE (val INT) INSERT INTO @t (val) VALUES (420),(420),(520),(520),(520),(620) --SELECT val,ROW_NUMBER()OVER(PARTITION BY val order by val)RN from @t DECLARE @t2 table (id INT identity(1,1), val INT, rn INT) DECLARE @val INT DECLARE @rn INT DECLARE @val_prev INT DECLARE CUR CURSOR FOR SELECT val ,ROW_NUMBER()OVER(PARTITION BY val ORDER BY val)RN FROM @t ORDER BY val ASC OPEN CUR FETCH NEXT FROM cur INTO @val, @rn SET @val_prev = @val WHILE @@FETCH_STATUS = 0 BEGIN IF @val_prev <> @val BEGIN INSERT @t2 (val,rn) VALUES (NULL, NULL) SET @val_prev = @val END INSERT @t2 (val,rn) VALUES (@val, @rn) FETCH NEXT FROM cur INTO @val, @rn END CLOSE cur; DEALLOCATE cur; SELECT * FROM @t2 ORDER BY id 使用NSLog() NSDate方法,该方法提供以GMT(UTC)为参考的日期/时间,并且description默认为您的时区,因此显示的日期可能是不同。