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
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