NSDateFormatter不会在NSDate中转换我的NSString

Question

我有一个字符串,需要将其转换为日期,但它不能正确转换.我不知道为什么...我的代码是:

NSString * fecha = @"2011-12-07 11:11:29.657";

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss.ZZZ"];

NSDate *dateFromString = [[NSDate alloc] init]; 
dateFromString = [dateFormatter dateFromString:fecha]; 

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
unsigned units = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;

NSDateComponents *components = [calendar components:units              
                                           fromDate:dateFromString];
 NSInteger* hour = [components hour];
 NSInteger* minute = [components minute];
 NSInteger* second = [components second];  

NSLog(@"Fecha: %@",fecha);
NSLog(@"Format: %@",dateFormatter.dateFormat);
NSLog(@"date: %@",dateFromString);

在我的日志中:

2011-12-07 11:36:11.750 Catalogo-V1[13741:207] Fecha: 2011-12-07 11:11:29.657
2011-12-07 11:36:11.750 Catalogo-V1[13741:207] Format: yyyy-MM-dd HH:mm:ss.ZZZ
2011-12-07 11:36:11.751 Catalogo-V1[13741:207] date: (null)

Answer 1

我想,而不是格式字符串的yyyy-MM-dd HH:mm:ss.ZZZ,你会想yyyy-MM-dd HH:mm:ss.SSS.

ZZZ将是时区值,而SSS是小数秒.

请参阅Unicode文档(从Apple的数据格式文档链接)

编辑:另一件事:你不需要行NSDate *dateFromString = [[NSDate alloc] init];.打电话吧NSDate *dateFromString = [dateFormatter dateFromString:fecha];.日期格式化程序将根据需要分配日期对象.