iOS存储实例对象

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);      NSString *documentsDirectory = [paths objectAtIndex:0];            NSString *filePath = [documentsDirectory stringByAppendingPathComponent:k_FILE_NAME];            NSMutableData *data = [[[NSMutableData alloc] init] autorelease];      NSKeyedArchiver *archiver = [[[NSKeyedArchiver alloc] initForWritingWithMutableData:data] autorelease];  UserEntity *userEntity = [[[UserEntity alloc] init] autorelease];      userEntity.age = 18;      userEntity.gender = NO;      userEntity.userName = @"add";

[archiver encodeObject:userEntity forKey:@"KEY"];      [archiver finishEncoding];      BOOL success = [data writeToFile:filePath atomically:YES];  

详见原文：http://blog.csdn.net/qq5306546/article/details/9240283