IOS设计模式-抽象工厂

抽象工厂的灵活性要比简单工程的灵活性强。

抽象工厂的UML图(第一次画UML图，可能关系和箭头的图意义有错误，但是请不要以建模规范去看图，以最基本的结合后面OC代码，理解相关关系)：

抽象工厂原理：
抽象工厂 较 简单工厂 多了抽象级别 而已。

因为需要创建抽象工厂，所以需要工厂管理器：
新建FactoryManager.h和FactoryManager.m:
FactoryManager.h:

 #import <Foundation/Foundation.h>
 #import "BaseFactory.h"
 #import "AppleFactory.h"
 #import "GoogleFactory.h"

 在抽象工厂类中为什么需要枚举列举工厂类，因为需要用户指定工厂，
 然后让工厂来生产具体产品
 typedef enum : NSUInteger {

     kApple   = 0x11,
     kGoogle,

 } EFactoryType;

 @interface FactoryManager : NSObject

 /**
  *  获取工厂
  *
  *  @param factoryType 工厂类型
  *
  *  @return 创建出的工厂
  */
 + (BaseFactory *)factoryWithBrand:(EFactoryType)factoryType;

 @end

FactoryManager.h

FactoryManager.m:

 #import "FactoryManager.h"

 @implementation FactoryManager

 + (BaseFactory *)factoryWithBrand:(EFactoryType)factoryType {

     BaseFactory *factory = nil;

     if (factoryType == kApple) {

         factory = [[AppleFactory alloc] init];

     } else if (factoryType == kGoogle) {

         factory = [[GoogleFactory alloc] init];
     }

     return factory;
 }

 @end

FactoryManager.m

===============================================
建立具体工厂对应的父类工厂：
BaseFactory.h:

 #import <Foundation/Foundation.h>
 #import "BasePhone.h"
 #import "BaseWatch.h"

 @interface BaseFactory : NSObject

 /**
  *  创建手机
  *
  *  @return 手机
  */
 - (BasePhone *)createPhone;

 /**
  *  创建手表
  *
  *  @return 手表
  */
 - (BaseWatch *)createWatch;

 @end

BaseFactory.h

BaseFactory.m:

 #import "BaseFactory.h"

 @implementation BaseFactory

 - (BasePhone *)createPhone {

     return nil;
 }

 - (BaseWatch *)createWatch {

     return nil;
 }

 @end

BaseFactory.m

========================================================
关于继承的细节：
继承来自父类的方法，就不需要在子类的@interface声明中重写，直接在@implementation实现中实现父类的方法
========================================================
根据继承上面父类工厂新建两个具体工厂子类AppleFactory和GoogleFactory子类：
AppleFactory.h
#import "BaseFactory.h"

@interface AppleFactory : BaseFactory

@end
AppleFactory.m
#import "AppleFactory.h"
#import "iPhone.h"
#import "iWatch.h"

@implementation AppleFactory

- (BasePhone *)createPhone {
    
    return [[iPhone alloc] init];
}

- (BaseWatch *)createWatch {
    
    return [[iWatch alloc] init];
}

@end
=========================================================
GoogleFactory.m
#import "BaseFactory.h"

@interface GoogleFactory : BaseFactory

@end

GoogleFactory.h
#import "GoogleFactory.h"
#import "Android.h"
#import "AndroidWatch.h"

@implementation GoogleFactory

- (BasePhone *)createPhone {
    
    return [[Android alloc] init];
}

- (BaseWatch *)createWatch {
    
    return [[AndroidWatch alloc] init];
}

@end

=========================================================
手机也有抽象的父类
BasePhone.h:
#import <Foundation/Foundation.h>

@interface BasePhone : NSObject

@end
BasePhone.m:
#import "BasePhone.h"

@implementation BasePhone

@end

=========================================================
手机具体的子类
iPhone.h
#import "BasePhone.h"

@interface iPhone : BasePhone

@end

iPhone.m
#import "iPhone.h"

@implementation iPhone

@end

=========================================================
Android.h
#import "BasePhone.h"

@interface Android : BasePhone

@end
Android.m
#import "Android.h"

@implementation Android

@end

=========================================================
手表抽象的类
BaseWatch.h
#import <Foundation/Foundation.h>

@interface BaseWatch : NSObject

@end
BaseWatch.m
#import "BaseWatch.h"

@implementation BaseWatch

@end

=========================================================
手表具体的类
iWatch.h

 #import "iWatch.h"

 @implementation iWatch

 @end

iWatch.h

iWatch.m

 #import "BaseWatch.h"

 @interface AndroidWatch : BaseWatch

 @end

 #import "AndroidWatch.h"

 @implementation AndroidWatch

 @end

iWatch.m

=========================================================
客户端程序>>>>ViewController.m:

 #import "ViewController.h"
 #import "FactoryManager.h"

 @interface ViewController ()

 @end

 @implementation ViewController

 - (void)viewDidLoad {

     [super viewDidLoad];

     // 获取工厂
     BaseFactory *factory = [FactoryManager factoryWithBrand:kGoogle];

     // 创建商品
     BasePhone *phone = [factory createPhone];
     BaseWatch *watch = [factory createWatch];

     NSLog(@"%@ %@", phone, watch);
 }

 @end

ViewController.m