获取文件的修改时间
NSDateFormatter *formatter = [[[NSDateFormatter alloc] init] autorelease]; [formatter setDateFormat:@"YYYY-MM-dd hh:mm:ss"]; NSDictionary* fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:[NSString stringWithFormat:@"%@/%@",kNotUploadXmlFolder, fileName] error:nil];NSDate* fileModifyDate = [fileAttributes objectForKey:NSFileModificationDate]; NSString* fileModityDateString=[formatter stringFromDate: fileModifyDate];?