Objective-C:协议protocol

六、协议(protocol)

关键字:@optional、@required

（1）是一个类共享的一个方法列表

（2）它声明了一系列的方法而不进行实现

（3）遵从某个协议，就是需要实现协议中的方法

（4）类似于java的接口、C++中的纯虚函数

非正式协议、正式协议

重点：正式协议:所有实现正式协议的类, 都必须实现该协议中的所有方法

一个类可以实现任意多个协议

协议其实就是代理模式：自己不亲自做，让别人去做，遵循了协议的类,可以成为别的类的代理。

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//Boos类,制定委托协议并选择委托人(Boos有些事可以自己做,但是有些事需要委托人去做,例如秘书帮助老板去买票、订房、通知开会的人)

 //  Boos.h
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>
 @protocol BossDeledate
 -(void)bookTicket;
 -(void)bookRoom;
 -(void)notify;
 @end
 @interface Boos : NSObject
 @property(nonatomic,weak)id<BossDeledate> delegate;
 -(void)travel;
 -(void)meeting;
 @end

 //  Boos.m
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import "Boos.h"

 @implementation Boos
 -(void)travel
 {
      //1、订机票
     [_delegate bookTicket];
      //2、订酒店
     [_delegate bookRoom];
      //3、去出差
     NSLog(@"Boss travel");
 }
 -(void)meeting
 {
      //1、通知开会的所有人
     [_delegate notify];
      //2、讲话
     NSLog(@"Boss talk");
 }
 @end

//选取person作为委托人

 //  Person.h
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>
 #import "Boos.h"
 @interface Person : NSObject<BossDeledate>

 @end

 //  Person.m
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 //

 #import "Person.h"

 @implementation Person
 -(void)bookTicket
 {
     NSLog(@"person book ticket");
 }
 -(void)bookRoom
 {
     NSLog(@"person book room");
 }
 -(void)notify
 {
     NSLog(@"person notify all people meeting!");
 }
 @end

//还可以选取Student作为代理人

 //  Student.h
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>
 #import "Boos.h"
 @interface Student : NSObject <BossDeledate>

 @end

 //  Student.m
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 //

 #import "Student.h"

 @implementation Student
 -(void)bookTicket
 {
     NSLog(@"student book ticket");
 }
 -(void)bookRoom
 {
     NSLog(@"student book room");
 }
 -(void)notify
 {
     NSLog(@"student notify all people meeting!");
 }
 @end

//测试代理人

 //  main.m
 //  04-Delegate
 //
 //  Created by ma c on 15/8/12.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>
 #import "Boos.h"
 #import "Person.h"
 #import "Student.h"
 int main(int argc, const char * argv[])
 {
     @autoreleasepool
     {
         //测试代理模式
         Boos *boss = [[Boos alloc]init];
         Person *person = [[Person alloc]init];
         Student *student = [[Student alloc]init];

         //老板设置代理
         [boss setDelegate:person];

         [boss meeting];
         [boss travel];

         //老板重新选择学生作为代理人
         [boss setDelegate:student];

         [boss meeting];
         [boss travel];
     }
     return ;
 }

//运行结果

-- ::23.663 -Delegate[:] person notify all people meeting!
-- ::23.664 -Delegate[:] Boss talk
-- ::23.664 -Delegate[:] person book ticket
-- ::23.665 -Delegate[:] person book room
-- ::23.665 -Delegate[:] Boss travel
-- ::23.665 -Delegate[:] student notify all people meeting!
-- ::23.665 -Delegate[:] Boss talk
-- ::23.665 -Delegate[:] student book ticket
-- ::23.665 -Delegate[:] student book room
-- ::23.666 -Delegate[:] Boss travel
Program ended with exit code: