NSCopying简析

用到NSCopying的时候并不多,但还是有必要知道最基本的用途,比方说数组的拷贝操作,需要注意的是,数组的拷贝操作并不是执行了 copy 方法,而是需要执行 initWithArray:copyItems: ,这点需要注意.

源码:

////  Model.h//  NSCopy////  Created by YouXianMing on 15/5/2.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import 
     
      @interface Model : NSObject 
      // 对象类型@property (nonatomic, strong) NSString  *name;@property (nonatomic, strong) NSNumber  *age;// 基本数据类型@property (nonatomic, assign) BOOL       isMale;@end
     

////  Model.m//  NSCopy////  Created by YouXianMing on 15/5/2.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import "Model.h"@implementation Model- (id)copyWithZone:(NSZone *)zone {        // 获取拷贝内容    Model *copy = [[[self class] allocWithZone:zone] init];        // 基本属性的类型本身实现了copy协议    copy.name = [_name copy];    copy.age  = [_age  copy];        // 常规类型属性仅仅需要赋值即可    copy.isMale = _isMale;        return copy;}@end

控制器源码:

////  ViewController.m//  NSCopy////  Created by YouXianMing on 15/5/2.//  Copyright (c) 2015年 YouXianMing. All rights reserved.//#import "ViewController.h"#import "Model.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // 对象1    Model *modelOne = [Model new];    modelOne.name   = @"YouXianMing";    modelOne.age    = @(28);            // 对象1的复制    Model *modelCopy = [modelOne copy];            // 打印信息    NSLog(@"%@ %@", modelOne, modelOne.name);    NSLog(@"%@ %@", modelCopy, modelCopy.name);            // 数组    NSArray *array = @[modelOne, modelCopy];            // 数组的复制    NSArray *arrayCopy = [[NSArray alloc] initWithArray:array copyItems:YES];            // 打印信息    NSLog(@"%@", array);    NSLog(@"%@", arrayCopy);}@end

简单的分析: