在iphone中获取格式化的时间

参看：http://blog.chinaunix.net/u2/66419/showart_2347823.html

NSDateFormatter *dateFormatter = [[NSDateFormatteralloc] init];
[dateFormatter setDateFormat:@"YYYY年MM月dd日"];
NSString *currentDate = [dateFormatter stringFromDate:[NSDatedate]];
NSLog(@"current date = %@",currentDate);