Objective-C 桥接模式 -- 简单实用和说明

桥接模式---把两个相关联的类抽象出来, 以达到解耦的目的

比如XBox遥控器跟XBox主机, 我们抽象出主机和遥控器两个抽象类, 让这两个抽象类耦合

然后生成这两个抽象类的实例XBox & XBox主机 以达到解耦

同时还能再继承为其他的游戏机

因为是控制器在控制主机, 所以控制器抽象类会持有主机抽象类

BaseControl.h

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

@interface BaseControl : NSObject

@property (nonatomic, strong) BaseGameSystem *gameSystem;

/**
 上下左右AB-方法
 */
- (void)up;
- (void)down;
- (void)left;
- (void)right;
- (void)commandA;
- (void)commandB;

@end

BaseControl.m

#import "BaseControl.h"

@implementation BaseControl

- (void)up {
    
    [self.gameSystem loadComand:kUp];
}

- (void)down {
    
    [self.gameSystem loadComand:kDown];
}

- (void)left {
    
    [self.gameSystem loadComand:kLeft];
}

- (void)right {
    
    [self.gameSystem loadComand:kRight];
}

- (void)commandA {
    
    [self.gameSystem loadComand:kA];
}

- (void)commandB {
    
    [self.gameSystem loadComand:kB];
}

@end

BaseGameSystem.h

#import <Foundation/Foundation.h>

typedef enum : NSUInteger {
    
    kUp = 0x1,
    kDown,
    kLeft,
    kRight,
    kA,
    kB,
    
    kO,
    kX
    
} EcomandType;

@interface BaseGameSystem : NSObject

/**
 加载指令

 @param type 指令代码
 */
- (void)loadComand:(EcomandType) type;

@end

BaseGameSystem.m

#import "BaseGameSystem.h"

@implementation BaseGameSystem

- (void)loadComand:(EcomandType)type {
    
}

@end

这样两个抽象类就耦合了, 现在我们创建实例

XBoxGameSystem.h

#import "BaseGameSystem.h"

@interface XBoxGameSystem : BaseGameSystem

@end

XboxGameSystem.m

#import "XBoxGameSystem.h"

@implementation XBoxGameSystem

- (void)loadComand:(EcomandType)type {
    
    switch (type) {
        case kUp:
            NSLog(@"UP");
            break;
        
        case kDown:
            NSLog(@"Down");
            break;
            
        case kRight:
            NSLog(@"Right");
            break;
        
        case kLeft:
            NSLog(@"Left");
            break;
        
        case kA:
            NSLog(@"kA");
            break;
        
        case kB:
            NSLog(@"kB");
            break;
        
        default:
            NSLog(@"None");
            break;
    }
}
@end

XBoxController.h

#import "BaseControl.h"

@interface XBoxController : BaseControl

@end

XBoxController.m

#import "XBoxController.h"

@implementation XBoxController

@end

下面是Controller中使用

#import "ViewController.h"
#import "BaseControl.h"
#import "XBoxGameSystem.h"
#import "XBoxController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    
    [super viewDidLoad];
    
    BaseControl *controller = [[XBoxController alloc] init];
    controller.gameSystem = [[XBoxGameSystem alloc] init];
    
    [controller up];
    
}



@end