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 0;
}

//运行结果

2015-08-12 15:04:23.663 04-Delegate[1223:70726] person notify all people meeting!
2015-08-12 15:04:23.664 04-Delegate[1223:70726] Boss talk
2015-08-12 15:04:23.664 04-Delegate[1223:70726] person book ticket
2015-08-12 15:04:23.665 04-Delegate[1223:70726] person book room
2015-08-12 15:04:23.665 04-Delegate[1223:70726] Boss travel
2015-08-12 15:04:23.665 04-Delegate[1223:70726] student notify all people meeting!
2015-08-12 15:04:23.665 04-Delegate[1223:70726] Boss talk
2015-08-12 15:04:23.665 04-Delegate[1223:70726] student book ticket
2015-08-12 15:04:23.665 04-Delegate[1223:70726] student book room
2015-08-12 15:04:23.666 04-Delegate[1223:70726] Boss travel
Program ended with exit code: 0