IOS学习笔记二十四(NSData归档多个对象和归档对象实现深复制)

1、NSData归档多个对象

一、之前我写的学习笔记都是归档一个对象，如果需要归档多个对象我们需要借助NSData

二、步骤

      1）、NSMutableData作为参数，构建 NSKeyedArchiver对象

      2）、调用NSKeyedArchiver的encodeXXX

      3)、调用NSKeyedArchiver的finishEncoding方法

      4)、NSMutableData保存到文件

 
2、归档对象实现深复制

   我们知道深复制就是复制对象和原始对象没有任何公用的部分，修改复制对象的值不会对原始对象产生影响。

步骤

1）、NSKeyedArchiver的archivedDataWithRootObject

2）、NSKeyedUnarchiver的unarchiveObjectWithData

 
 
3、实现Demo

 IApple.h

    #import <Foundation/Foundation.h>
    #ifndef IApple_h
    #define IApple_h
    @interface IApple : NSObject <NSCoding>
    @property (nonatomic, copy) NSString *color;
    @property (nonatomic, assign) double weight;
    @property (nonatomic, assign) int size;
    -(id)initWithColor:(NSString *) color weight:(double) weight size:(int) size;
    @end
     
    #endif /* IApple_h */

 
IApple.m

    #import  "IApple.h"
    #import <Foundation/Foundation.h>
    @implementation IApple
    @synthesize color = _color;
    @synthesize weight = _weight;
    @synthesize size = _size;
    -(id)initWithColor:(NSString *) color weight:(double) weight size:(int) size
    {
        if (self = [super init])
        {
            self.color = color;
            self.weight = weight;
            self.size = size;
        }
        return self;
    }
    -(NSString *)description
    {
        return [NSString stringWithFormat:@"<IApple [color = %@, weight = %g, _size = %d]>", self.color, self.weight, self.size];
    }
     
    -(void)encodeWithCoder:(NSCoder *)aCoder
    {
        [aCoder encodeObject:_color forKey:@"color"];
        [aCoder encodeDouble:_weight forKey:@"weight"];
        [aCoder encodeInt:_size forKey:@"size"];
    }
    -(id) initWithCoder:(NSCoder *)aDecoder
    {
        _color = [aDecoder decodeObjectForKey:@"color"];
        _weight = [aDecoder decodeDoubleForKey:@"weight"];
        _size = [aDecoder decodeIntForKey:@"size"];
        return self;
    }
     
    @end

 

main.m

    #import "IApple.h"
    int main(int argc, char * argv[]) {
        @autoreleasepool {
            NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:80], @"java", [NSNumber numberWithInt:90], @"c", [NSNumber numberWithInt:70], @"oc", [NSNumber numberWithInt:100], @"c++",nil];
            NSSet *set = [NSSet setWithObjects:@"java", @"ios", @"c++", @"oc", nil];
            IApple *apple = [[IApple alloc] initWithColor:@"red" weight:50 size:20];
            
            NSMutableData *data = [NSMutableData data];
            NSKeyedArchiver *arch = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
            //归档对象
            [arch encodeObject:dict forKey:@"dict"];
            [arch encodeObject:set forKey:@"set"];
            [arch encodeObject:apple forKey:@"apple"];
            //结束归档
            [arch finishEncoding];
        
            //在document目录下创建一个chenyu.txt空文件
            NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *path = [docPaths objectAtIndex:0];
            NSLog(@"document path:%@", path);
            
            NSFileManager *fileManager = [NSFileManager defaultManager];
            NSString *chenyuPath = [path stringByAppendingPathComponent:@"chenyu.txt"];
            BOOL isSuccess = [fileManager createFileAtPath:chenyuPath contents:nil attributes:nil];
            if (isSuccess) {
                NSLog(@"make chenyu.txt success");
            } else {
                NSLog(@"make chenyu.txt fail");
            }
            
            //归档对象到chenyu.txt文件
            if([data writeToFile:chenyuPath atomically:YES] == YES)
            {
                NSLog(@"归档对象成功");
            }
            else
            {
                NSLog(@"归档对象失败");
            }
            
            //读取归档对象
            NSData *readData = [NSData dataWithContentsOfFile:chenyuPath];
            NSKeyedUnarchiver *unArch = [[NSKeyedUnarchiver alloc] initForReadingWithData:readData];
            NSDictionary *readDict = [unArch decodeObjectForKey:@"dict"];
            NSSet *readSet = [unArch decodeObjectForKey:@"set"];
            NSSet *readApple = [unArch decodeObjectForKey:@"apple"];
            NSLog(@"readDict is:%@", readDict);
            NSLog(@"readSet is:%@", readSet);
            NSLog(@"readApple is %@", readApple);
            
            //使用归档对戏实现深复制 深复制就是复制对象和本身对象没有任何公用部分，所以修改复制对象的属性不会影响原始对象的属性
            NSDictionary *diction = [NSDictionary dictionaryWithObjectsAndKeys:[[IApple alloc] initWithColor:@"red" weight:50 size:20], @"one", [[IApple alloc] initWithColor:@"green" weight:60 size:21], @"two", nil];
            //对象归档
            NSData *data1 = [NSKeyedArchiver archivedDataWithRootObject:diction];
            //回复对象
            NSDictionary *dictCopy = [NSKeyedUnarchiver unarchiveObjectWithData:data1];
            IApple *app = [dictCopy objectForKey:@"one"];
            [app setColor:@"green"];
            IApple *app1 = [diction objectForKey:@"one"];
            NSLog(@"app1 color is:%@", app1.color);
        }
    }


 
4、运行结果

    2018-07-22 19:34:11.258816+0800 cyTest[62704:16613816] document path:*****/3FF9B833-FAF8-4C30-A855-3D40A4EAE8A6/data/Containers/Data/Application/6AD520C9-3A99-45B5-A2F9-4E4D7CA77486/Documents
    2018-07-22 19:34:11.269539+0800 cyTest[62704:16613816] make chenyu.txt success
    2018-07-22 19:34:11.271898+0800 cyTest[62704:16613816] 归档对象成功
    2018-07-22 19:34:11.272976+0800 cyTest[62704:16613816] readDict is:{
        c = 90;
        "c++" = 100;
        java = 80;
        oc = 70;
    }
    2018-07-22 19:34:11.273243+0800 cyTest[62704:16613816] readSet is:{(
        "c++",
        java,
        ios,
        oc
    )}
    2018-07-22 19:34:11.273602+0800 cyTest[62704:16613816] readApple is <IApple [color = red, weight = 50, _size = 20]>
    2018-07-22 19:34:11.274150+0800 cyTest[62704:16613816] app1 color is:red

 




 

 
作者：chen.yu
深信服三年半工作经验，目前就职游戏厂商，希望能和大家交流和学习,
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