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