版本记录

版本号	时间
V1.0	2017.04.27

前言

前面讲了23种设计模式中的前几个，下面我们继续，先看前几篇文章。
1. 23种设计模式（一)
2. 23种设计模式（二）
3. 23种设计模式（三)
4. 23种设计模式（四)

详述

八、建造者模式——Builder

  将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。

先看代码组织结构。

代码组织结构

看代码。

1. ViewController.m

#import "ViewController.h"
#import "HCDPersonBuilderDirector.h"
#import "HCDPersonFatBuilder.h"
#import "HCDPersonThinBuilder.h"
#import "HCDPresionBuilder.h"

typedef id<HCDPresionBuilder> HCDPresionBuilder;

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    HCDPresionBuilder builder = [[HCDPersonFatBuilder alloc]init];
    HCDPersonBuilderDirector *fatDirector = [[HCDPersonBuilderDirector alloc]initWithPersonBuilder:builder];
    [fatDirector buildPerson];
}

@end

2. HCDPersonBuilderDirector.h

#import <Foundation/Foundation.h>
#import "HCDPresionBuilder.h"

@interface HCDPersonBuilderDirector : NSObject

- (instancetype)initWithPersonBuilder:(id<HCDPresionBuilder>)builder;

- (void)buildPerson;

@end

3. HCDPersonBuilderDirector.m

#import "HCDPersonBuilderDirector.h"

@interface HCDPersonBuilderDirector ()

@property (nonatomic, strong) id<HCDPresionBuilder> builder;

@end

@implementation HCDPersonBuilderDirector

- (instancetype)initWithPersonBuilder:(id<HCDPresionBuilder>)builder
{
    self = [super init];
    if (self) {
        _builder = builder;
    }
    return self;
}

- (void)buildPerson
{
    [self.builder buildHead];
    [self.builder buildBody];
    [self.builder buildArmLeft];
    [self.builder buildArmRight];
    [self.builder buildLegLeft];
    [self.builder buildLegRight];
}

@end

4. HCDPersonFatBuilder.h

#import <Foundation/Foundation.h>
#import "HCDPresionBuilder.h"

@interface HCDPersonFatBuilder : NSObject <HCDPresionBuilder>

@end

5. HCDPersonFatBuilder.m

#import "HCDPersonFatBuilder.h"

@implementation HCDPersonFatBuilder

- (void)buildHead
{
    NSLog(@"建造胖子的头部");
}

- (void)buildBody
{
    NSLog(@"建造胖子的身体");
}

- (void)buildArmLeft
{
    NSLog(@"建造胖子的左手");
}

- (void)buildArmRight
{
    NSLog(@"建造胖子的右手");
}

- (void)buildLegLeft
{
    NSLog(@"建造胖子的左脚");
}

- (void)buildLegRight
{
    NSLog(@"建造胖子的右脚");
}

@end

6. HCDPersonThinBuilder.h

#import <Foundation/Foundation.h>
#import "HCDPresionBuilder.h"

@interface HCDPersonThinBuilder : NSObject<HCDPresionBuilder>

@end

7. HCDPersonThinBuilder.m

#import "HCDPersonThinBuilder.h"

@implementation HCDPersonThinBuilder

- (void)buildHead
{
    NSLog(@"建造瘦子的头部");
}

- (void)buildBody
{
    NSLog(@"建造瘦子的身体");
}

- (void)buildArmLeft
{
    NSLog(@"建造瘦子的左手");
}

- (void)buildArmRight
{
    NSLog(@"建造瘦子的右手");
}

- (void)buildLegLeft
{
    NSLog(@"建造瘦子的左脚");
}

- (void)buildLegRight
{
    NSLog(@"建造瘦子的右脚");
}

@end

8. HCDPresionBuilder.h

#import <Foundation/Foundation.h>

@protocol HCDPresionBuilder <NSObject>

- (void)buildHead;

- (void)buildBody;

- (void)buildArmLeft;

- (void)buildArmRight;

- (void)buildLegLeft;

- (void)buildLegRight;

@end

看结果。

2017-04-26 23:26:13.864 8建造者模式[847:13428] 建造胖子的头部
2017-04-26 23:26:13.864 8建造者模式[847:13428] 建造胖子的身体
2017-04-26 23:26:13.865 8建造者模式[847:13428] 建造胖子的左手
2017-04-26 23:26:13.866 8建造者模式[847:13428] 建造胖子的右手
2017-04-26 23:26:13.866 8建造者模式[847:13428] 建造胖子的左脚
2017-04-26 23:26:13.867 8建造者模式[847:13428] 建造胖子的右脚

结论：自己注意思想吧。

---

九、观察者模式——Observer

  定义了一种一对多的依赖关系，让多个观察者对象同时监听某一个主题对象。这个主题对象在状态发生变化时，会通知所有观察者对象，使它们能够自动更新自己。

看代码结构。

代码结构

看代码。

1. ViewController.m

#import "ViewController.h"
#import "HCDObserver.h"
#import "HCDNBAObserver.h"
#import "HCDStockObserver.h"
#import "HCDSecreteSubject.h"

typedef id<HCDObserver> HCDObserver;

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    HCDSubject *subject = [[HCDSecreteSubject alloc]init];
    //添加三个通知对象
    HCDObserver nbaobserver = [[HCDNBAObserver alloc]init];
    [subject attach:nbaobserver];
    HCDObserver stockobserver = [[HCDStockObserver alloc]init];
    [subject attach:stockobserver];
    HCDObserver stockobserver1 = [[HCDStockObserver alloc]init];
    [subject attach:stockobserver1];
    //删除一个通知对象
    [subject detach:stockobserver];
    
    [subject notify];
    
}

@end

2. HCDSubject.h

#import <Foundation/Foundation.h>
#import "HCDObserver.h"

@interface HCDSubject : NSObject

- (void)attach:(id<HCDObserver>)observer;

- (void)detach:(id<HCDObserver>)observer;

- (void)notify;

- (NSArray *)getobserverList;

@end

3. HCDSubject.m

#import "HCDSubject.h"

@interface HCDSubject ()

@property (nonatomic, readwrite, strong) NSMutableArray *observerList;

@end


@implementation HCDSubject

- (instancetype)init
{
    self = [super init];
    if (self) {
        _observerList = [NSMutableArray array];
    }
    return self;
}

- (void)attach:(id<HCDObserver>)observer
{
    [self.observerList addObject:observer];
}

- (void)detach:(id<HCDObserver>)observer
{
    for (id<HCDObserver> currentObserver in [self getobserverList]) {
        if (currentObserver == observer) {
            [self.observerList removeObject:observer];
        }
    }
}

- (NSMutableArray *)getobserverList
{
    return [NSMutableArray arrayWithArray:self.observerList];
}

- (void)notify
{
    
}

@end

4. HCDSecreteSubject.h

#import "HCDSubject.h"

@interface HCDSecreteSubject : HCDSubject

@end

5. HCDSecreteSubject.m

#import "HCDSecreteSubject.h"
#import "HCDObserver.h"

@implementation HCDSecreteSubject

- (void)notify
{
    NSLog(@"秘书通知：老板回来了，大家赶紧撤");
    for (id <HCDObserver> observer in [self getobserverList]) {
        [observer update];
    }
}

@end

6. HCDObserver.h

#import <Foundation/Foundation.h>

@protocol HCDObserver <NSObject>

@optional

- (void)update;

@end

7. HCDStockObserver.h

#import <Foundation/Foundation.h>
#import "HCDObserver.h"

@interface HCDStockObserver : NSObject <HCDObserver>

@end

8. HCDStockObserver.m

#import "HCDStockObserver.h"

@implementation HCDStockObserver

- (void)update
{
    NSLog(@"操。。老板回来了,带会儿再看");
}

@end

9. HCDNBAObserver.h

#import <Foundation/Foundation.h>
#import "HCDObserver.h"

@interface HCDNBAObserver : NSObject <HCDObserver>

@end

10. HCDNBAObserver.m

#import "HCDNBAObserver.h"

@implementation HCDNBAObserver

- (void)update
{
    NSLog(@"擦，老板回来了，待会儿继续看NBA");
}

@end

看答案。

2017-04-26 23:39:50.296 9观察者模式[1086:21539] 秘书通知：老板回来了，大家赶紧撤
2017-04-26 23:39:50.296 9观察者模式[1086:21539] 擦，老板回来了，待会儿继续看NBA
2017-04-26 23:39:50.296 9观察者模式[1086:21539] 操。。老板回来了,带会儿再看

结论：自己看思想。

后记

  未完，待续，谢谢大家对我的支持，希望我写的这些东西能对大家有好处，拿一张风景图养养眼吧。

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