iOS设计模式－原型模式

定义：用原型实例指定创建对象的种类，在运行时抽象子类任何对象都可以按照客户端的意愿被复制。

注：通俗一点讲就是通过拷贝的方式快速复制该类一个对象

类型：对象创建

注：对象的拷贝分为浅拷贝和深拷贝，浅拷贝是指指针拷贝，或者对于有层级的对象拷贝时，有部分层级是浅拷贝（如数组，对数组是深拷贝，但对数组中的对象是浅拷贝，也属于浅拷贝的范畴），深拷贝不光拷贝指针还拷贝在内存中的指向的对象。

应用场景 

 

#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCopyin,NSMutableCopying>
@property(nonatomic, copy)NSString *name;
@property(nonatomic, assign)NSInteger age;

- (id)copyWithZone:(NSZone *)zone;
- (id)mutableCopyWithZone:(NSZone *)zone;

- (void)copyProperty:(Person *)person;

@end

#import "Person.h"

@implementation Person

- (void)copyProperty:(Person *)person{
    person.name = _name;
    person.age = _age;
}

- (id)copyWithZone:(NSZone *)zone{
    Person *person = [[self class] allocWithZone:zone];
    [self copyProperty:person];
    return person;
}

- (id)mutableCopyWithZone:(NSZone *)zone{
    Person *person = [[self class] allocWithZone:zone];
    [self copyProperty:person];
    return person;
}

#import "Person.h"

@interface Programmer : Person
@property(nonatomic, copy)NSString *skill;
@end

#import "Programmer.h"

@implementation Programmer

- (void)copyProperty:(Programmer *)person{
    [super copyProperty:person];
     person.skill = _skill;
}

- (id)copyWithZone:(NSZone *)zone{
    Programmer *programmer = [[self class] allocWithZone:zone];
    [self copyProperty:programmer];
    return programmer;
}

- (id)mutableCopyWithZone:(NSZone *)zone{
    Programmer *programmer = [[self class] allocWithZone:zone];
    [self copyProperty:programmer];
    return programmer;
}

    测试
    Programmer *programmer = [[Programmer alloc]init];
    
    programmer.name = @"Hello world!";
    
    Programmer *programmer1 = programmer;
    
    Programmer *programmer2 = [programmer copy];
    
    programmer.name = @"hello iOS!";
    
    NSLog(@"%@ == %@ == %@",programmer.name,programmer1.name,programmer2.name);

2016-08-08 17:45:35.446 DesignPatternsDemo[7148:779654] hello iOS! == hello iOS! == Hello world!