107，Protocol在代理设计模式中应用

StudentProtocol.h:

#import <Foundation/Foundation.h>

//只有具备找房子的代理，才能为学生找房子，所以，让代理遵守该协议

@protocol StudentProtocol <NSObject>

-(void)helpStudentFindHouse;

@end

Student.h:

#import <Foundation/Foundation.h>

#import "LoveHouse.h"

#import "StudentProtocol.h"

@interface Student : NSObject

//使用id接收不同的对象，这样就有很多的扩展性了

@property(nonatomic,strong)id<StudentProtocol> delegate;

-(void)findHouse;

@end

Student.m:

#import "Student.h"

@implementation Student

-(void)findHouse{

    NSLog(@"学生找房子");

    if ([self.delegaterespondsToSelector:@selector(helpStudentFindHouse)]) {

        [self.delegatehelpStudentFindHouse];

    }

}

@end

SameCity.h:

#import <Foundation/Foundation.h>

#import "StudentProtocol.h"

@interface SameCity : NSObject <StudentProtocol>

@end

SameCity.m:

#import "SameCity.h"

@implementation SameCity

-(void)helpStudentFindHouse{

    NSLog(@"SameCity帮学生找房子！");

}

@end

LoveHouse.h:

#import <Foundation/Foundation.h>

#import "StudentProtocol.h"

@interface LoveHouse : NSObject <StudentProtocol>

-(void)helpStudentFindHouse;

@end

LoveHouse.m:

#import "LoveHouse.h"

@implementation LoveHouse

-(void)helpStudentFindHouse{

    NSLog(@"LoveHouse帮学生找房子！");

}

@end

main:

#import <Foundation/Foundation.h>

#import "Student.h"

#import "LoveHouse.h"

#import "SameCity.h"

/*

 使用代理设计模式，帮学生找房子

 */

int main(int argc,const char * argv[]) {

    

    Student *student = [Studentnew];

    LoveHouse *loveHouse = [LoveHousenew];

    student.delegate = loveHouse;

    [student findHouse];

    

    NSLog(@"------------");

    

    //代理人改为【同城】帮忙找房

    SameCity *sameCity = [SameCitynew];

    student.delegate = sameCity;

    [student findHouse];

    return 0;

}

//2015-12-19 11:53:43.470 2，代理设计模式[2058:80563]学生找房子

//2015-12-19 11:53:43.471 2，代理设计模式[2058:80563] LoveHouse帮学生找房子！

//2015-12-19 11:53:43.471 2，代理设计模式[2058:80563] ------------

//2015-12-19 11:53:43.471 2，代理设计模式[2058:80563]学生找房子

//2015-12-19 11:53:43.471 2，代理设计模式[2058:80563] SameCity帮学生找房子！

//Program ended with exit code: 0

main: