生成器模式——设计模式系列

        生成器模式有两个核心概念，一个是Director（指导者）、一个是Builder（生成器）。Builder知道如何在缺少某些特定信息的情况下建造产品，Director知道Builder应该建造什么，以参数向其提供缺少的信息来建造特定产品。生成器关注分步创建复杂对象，在最后一步返回产品。以下以代码进行说明。

//最终产品

@interface Character : NSObject 

{

 @private

 float protection_;

 float power_;

 float strength_;

 float stamina_;

 float intelligence_;

 float agility_;

 float aggressiveness_;

}

@end

=================================================================

//父类Builder

@interface CharacterBuilder : NSObject 

{

 @protected

 Character *character_;

}

@property (nonatomic,readonly) Character *character;

- (CharacterBuilder *) buildNewCharacter;

- (CharacterBuilder *) buildStrength:(float) value;

- (CharacterBuilder *) buildStamina:(float) value;

- (CharacterBuilder *) buildIntelligence:(float) value;

- (CharacterBuilder *) buildAgility:(float) value;

- (CharacterBuilder *) buildAggressiveness:(float) value;

@end

=================================================================

//实现类Builder

@interface StandardCharacterBuilder : CharacterBuilder 

{

}

// overriden methods from the abstract CharacterBuilder

- (CharacterBuilder *) buildStrength:(float) value;

- (CharacterBuilder *) buildStamina:(float) value;

- (CharacterBuilder *) buildIntelligence:(float) value;

- (CharacterBuilder *) buildAgility:(float) value;

- (CharacterBuilder *) buildAggressiveness:(float) value;

@end

=================================================================

//Director

@interface ChasingGame : NSObject 

{

}

- (Character *) createPlayer:(CharacterBuilder *) builder;

- (Character *) createEnemy:(CharacterBuilder *) builder;

@end

=================================================================

//客户端调用代码

- (void)viewDidLoad 

{

  [superviewDidLoad];

 CharacterBuilder *characterBuilder = [[[StandardCharacterBuilderalloc] init] autorelease];

 ChasingGame *game = [[[ChasingGamealloc] init] autorelease];

  Character *player = [game createPlayer:characterBuilder];

  Character *enemy = [game createEnemy:characterBuilder];

 // do something else with the

 // player and enemey

}