objective-c - 通过替换当前年份来转换日期字符串会给出错误的结果

Question

我有值为“29/01/2010”的 NSString，我想将其转换为 NSDate，并将年份值替换为当前年份。

为此，我尝试过

    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *components = [[NSDateComponents alloc] init];
    [components setYear:2013];
    [components setMonth:01];
    [components setDay:29];
    NSLog(@"%@",[calendar dateFromComponents:components]);

它给出的结果是2013-01-28 18:30:00 +0000

另一种尝试的方法是

     NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy"];
    NSString *yearString = [formatter stringFromDate:[NSDate date]];

    NSArray *dateComponents = [aStrBirthDate componentsSeparatedByString:@"/"];
    aStrBirthDate = [aStrBirthDate stringByReplacingOccurrencesOfString:[dateComponents lastObject] withString:yearString];

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"dd/MM/yyyy"];
    NSDate *dateFromString = [[NSDate alloc] init];
    dateFromString = [dateFormatter dateFromString:aStrBirthDate];

这也给出了相同的结果2013-01-28 18:30:00 +0000