15-02-28-protocol-@protocol interface

//

Main.m

05-protoco

//

Created by Apple on 13-8-11.

Copyright (c) 2013 itcast. All rights reserved.

//

/*

1. Definition of the Agreement

@protocol Agreement name <NSObject>

Method declaration List ....

@end

2. How to comply with the agreement

1> Class Compliance Agreement

@interface Class Name: Parent class name < protocol name 1, protocol name 2>

@end

2> Protocol Compliance Agreement

@protocol Agreement name < Other protocol name 1, other protocol name 2>

@end

3. Keywords for method declarations in the agreement

1> @required (default)

Requires implementation, and if not implemented, a warning is issued

2> @optional

Does not require implementation, how can there be no warning

4. When defining a variable, limit the object that this variable holds to a protocol

Class name < protocol name > * variable name;

id< protocol name > variable name;

Nsobject<myprotocol> *obj;

Id<myprotocol> Obj2;

If the corresponding protocol is not followed, the compiler warns

The attributes declared in [email protected] can also be used as a limit to comply with the agreement

@property (Nonatomic, Strong) class name < protocol name > * attribute name;

@property (nonatomic, strong) id< protocol name > attribute name;

@property (nonatomic, strong) dog<myprotocol> *dog;

@property (nonatomic, strong) id<myprotocol> dog2;

6. The agreement can be defined in a separate. h file and can also be defined in a class

1> If this protocol is used only in a class, the protocol should be defined in that class

2> If this protocol is used in many classes, it should be defined in a separate file

7. Classifications can be defined in separate. h and. m files and can also be defined in the original class

1> in general, are defined in a separate file

2> defines the classification in the original class, only requires the ability to read the grammar

*/

#import <Foundation/Foundation.h>

#import "MyProtocol.h"

#import "MyProtocol3.h"

#import "Person.h"

#import "Dog.h"

#import "Hashiqi.h"

int main ()

{

Person *p = [[Person alloc] init];

P.obj = [[Hashiqi alloc] init];

return 0;

}

void Test ()

{

NSObject *obj = [[NSObject alloc] init];

NSObject *obj2 = @ "4324324";

The object required for OBJ3 to be preserved must be myprotocol this protocol

nsobject<myprotocol> *obj3 = [[NSObject alloc] init];

nsobject<myprotocol> *obj3 = [[Person alloc] init];

Obj3 = nil;

id<myprotocol> OBJ4 = [[Person alloc] init];

Obj4 = nil;

Requires Obj5, the saved object must obey MyProtocol3, and inherit the person

person<myprotocol3> *obj5 = [[Person alloc] init];

Obj5 = nil;

}

15-02-28-protocol [email protected] interface