NSDateFormatter返回null

currentArticle.createdTime

data.createdTime

nil

dateFormat

-setDateFormat:

dateFormatter

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: @\"yyyyMMdd\"];

NSDate *date = data.createdTime;

NSLog(@\"   Normal Date = %@\", date);
NSLog(@\"Formatted Date = %@\", [dateFormatter stringFromDate: date]);

[dateFormatter release];

date

nil

NSLog()

data.createdTime

NSDate

NSString

-description

NSLog()

BOOL isDate = [data.createdTime isKindOfClass: [NSDate class]];
NSLog(@\"Date %@ a date.\", isDate ? @\"is\" : @\"is not\");

[dateFormat setDateFormat:@\"yyyyMMdd\"];

[dateFormatter setDateFormat:@\"yyyyMMdd\"];

data.createdTime;

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@\"yyyyMMdd\"];

NSDate *date = [NSDate date];

NSLog(@\"%@\",date);
NSLog(@\"%@\",[dateFormatter stringFromDate:date]);