NsDate格式化程序从字符串给出错误的日期

我有以下代码，它采用NSString并返回NSDate。 我已经从一个完全正常运行的项目中复制了这个代码 – 但是有些如何给我错误的输出

- (NSDate *)dateFromString:(NSString *)date { static NSDateFormatter *dateFormatter; if (!dateFormatter) { dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"dd-MM-yyyy"]; } NSLog(@"Date: %@ Formatted: %@",date,[dateFormatter dateFromString:date]); return [dateFormatter dateFromString:date]; } 

输出来自日志：

 Date: 07-01-2014 Formatted: 2014-01-06 18:30:00 +0000 Date: 24-01-2014 Formatted: 2014-01-23 18:30:00 +0000 Date: 06-01-2014 Formatted: 2014-01-05 18:30:00 +0000 Date: 15-01-2014 Formatted: 2014-01-14 18:30:00 +0000 Date: 22-01-2014 Formatted: 2014-01-21 18:30:00 +0000 Date: 31-01-2014 Formatted: 2014-01-30 18:30:00 +0000 Date: 14-01-2014 Formatted: 2014-01-13 18:30:00 +0000 Date: 30-01-2014 Formatted: 2014-01-29 18:30:00 +0000 

奇怪的是，它也在改变日期.. !! 任何帮助…… !!!

Answer 1

结果是格林威治标准时间输出结果 – 即如果您距格林威治标准时间5：3小时。

如果您希望在该时区中返回格式化日期，则需要指定时区:(这就是+0000的含义）

 - (NSDate *)dateFromString:(NSString *)date { static NSDateFormatter *dateFormatter; if (!dateFormatter) { dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]]; [dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]]; [dateFormatter setDateFormat:@"dd-MM-yyyy"]; } NSLog(@"Date: %@ Formatted: %@",date,[dateFormatter dateFromString:date]); return [dateFormatter dateFromString:date]; } 

Answer 2

检查一下

 - (NSDate *)dateFromString:(NSString *)date { static NSDateFormatter *dateFormatter; if (!dateFormatter) { dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"dd-MM-yyyy"]; } NSDate *dateValue= [dateFormatter dateFromString:date]; NSLog(@"Date: %@ Formatted: %@",date,[dateFormatter stringFromDate:dateValue]); return dateValue; }