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

 1 #import <Foundation/Foundation.h>
 2 #import "BaseGameSystem.h"
 3
 4 @interface BaseControl : NSObject
 5
 6 @property (nonatomic, strong) BaseGameSystem *gameSystem;
 7
 8 /**
 9  上下左右AB-方法
10  */
11 - (void)up;
12 - (void)down;
13 - (void)left;
14 - (void)right;
15 - (void)commandA;
16 - (void)commandB;
17
18 @end

BaseControl.m

 1 #import "BaseControl.h"
 2
 3 @implementation BaseControl
 4
 5 - (void)up {
 6
 7     [self.gameSystem loadComand:kUp];
 8 }
 9
10 - (void)down {
11
12     [self.gameSystem loadComand:kDown];
13 }
14
15 - (void)left {
16
17     [self.gameSystem loadComand:kLeft];
18 }
19
20 - (void)right {
21
22     [self.gameSystem loadComand:kRight];
23 }
24
25 - (void)commandA {
26
27     [self.gameSystem loadComand:kA];
28 }
29
30 - (void)commandB {
31
32     [self.gameSystem loadComand:kB];
33 }
34
35 @end

BaseGameSystem.h

 1 #import <Foundation/Foundation.h>
 2
 3 typedef enum : NSUInteger {
 4
 5     kUp = 0x1,
 6     kDown,
 7     kLeft,
 8     kRight,
 9     kA,
10     kB,
11
12     kO,
13     kX
14
15 } EcomandType;
16
17 @interface BaseGameSystem : NSObject
18
19 /**
20  加载指令
21
22  @param type 指令代码
23  */
24 - (void)loadComand:(EcomandType) type;
25
26 @end

BaseGameSystem.m

1 #import "BaseGameSystem.h"
2
3 @implementation BaseGameSystem
4
5 - (void)loadComand:(EcomandType)type {
6
7 }
8
9 @end

这样两个抽象类就耦合了, 现在我们创建实例

XBoxGameSystem.h

1 #import "BaseGameSystem.h"
2
3 @interface XBoxGameSystem : BaseGameSystem
4
5 @end

XboxGameSystem.m

 1 #import "XBoxGameSystem.h"
 2
 3 @implementation XBoxGameSystem
 4
 5 - (void)loadComand:(EcomandType)type {
 6
 7     switch (type) {
 8         case kUp:
 9             NSLog(@"UP");
10             break;
11
12         case kDown:
13             NSLog(@"Down");
14             break;
15
16         case kRight:
17             NSLog(@"Right");
18             break;
19
20         case kLeft:
21             NSLog(@"Left");
22             break;
23
24         case kA:
25             NSLog(@"kA");
26             break;
27
28         case kB:
29             NSLog(@"kB");
30             break;
31
32         default:
33             NSLog(@"None");
34             break;
35     }
36 }
37 @end

XBoxController.h

1 #import "BaseControl.h"
2
3 @interface XBoxController : BaseControl
4
5 @end

XBoxController.m

1 #import "XBoxController.h"
2
3 @implementation XBoxController
4
5 @end

下面是Controller中使用

 1 #import "ViewController.h"
 2 #import "BaseControl.h"
 3 #import "XBoxGameSystem.h"
 4 #import "XBoxController.h"
 5
 6 @interface ViewController ()
 7
 8 @end
 9
10 @implementation ViewController
11
12 - (void)viewDidLoad {
13
14     [super viewDidLoad];
15
16     BaseControl *controller = [[XBoxController alloc] init];
17     controller.gameSystem = [[XBoxGameSystem alloc] init];
18
19     [controller up];
20
21 }
22
23
24
25 @end