我正在尝试将 NString 转换为 NSData 但我不明白......怎么了?
NSString* createAt = @"Wed May 16 06:42:05 +0000 2012";
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:@"eee, dd MMM yyyy HH:mm:ss ZZZZ yyyy"];
NSDate *currentDate = [df dateFromString:createAt]; //returns nil