IOS学习笔记二十三对象归档(NSKeyedArchiver、NSKeyedUnArchiver、NSCodeing)

发布时间：2023-03-27 11:14:15 所属栏目：教程来源：

导读：NSKeyedArchiver、NSKeyedUnArchiver1）、archiveRootObject:toFile 归档对象到这个路径文件2）、unarchiveObjectWithFile:从这个路径文件把对象进行恢复对象归档这里我们可以理解Android里面的序列化，就是把对象保

NSKeyedArchiver、NSKeyedUnArchiver1）、archiveRootObject:toFile 归档对象到这个路径文件2）、unarchiveObjectWithFile:从这个路径文件把对象进行恢复对象归档这里我们可以理解Android里面的序列化，就是把对象保存到文件持久化，Android里面进行持久化的必须实现Serializable和Parcela...

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1、NSKeyedArchiver、NSKeyedUnArchiver
1）、archiveRootObject:toFile 归档对象到这个路径文件

2）、unarchiveObjectWithFile:从这个路径文件把对象进行恢复

对象归档这里我们可以理解Android里面的序列化，就是把对象保存到文件持久化，Android里面进行持久化的必须实现Serializable和Parcelable，然后IOS里面持久化必须实现NSCodeing协议，IOS进行持久化操作一般需要NSKeyedArchiver实现。

2、NSCodeing协议
1）、initWithCoder：该方法恢复对象

2）、encodeWithCoder：归档该对象

3、测试Demo(把Dictionary和普通对象进行对象归档)
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 {


//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");
}

//用NSKeyedArchiver进行对象归档
NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:10],@"oc",[NSNumber numberWithInt:20],@"java",[NSNumber numberWithInt:30],@"c++",nil];
[NSKeyedArchiver archiveRootObject:dic toFile:chenyuPath];
NSLog(@"123");
//利用NSKeyedUnarchiver进行恢复对象
NSDictionary *dic1 = [NSKeyedUnarchiver unarchiveObjectWithFile:chenyuPath];
NSLog(@"oc value is %@",[dic1 valueForKey:@"oc"]);
NSLog(@"java value is %@",[dic1 valueForKey:@"java"]);
NSLog(@"c++ value is %@",[dic1 valueForKey:@"c++"]);
//我们先看下chenyu.txt是什么文件，我们用file命令看下 file chenyu.txt,发现是二进制文件
// file chenyu.txt
// chenyu.txt: Apple binary property list
//下面为chenyu.txt文件的内容，我是用vim打开的
// bplist00Ô^A^B^C^D^E^F^Z^[X$versionX$objectsY$archiverT$top^R^@^A<86> ¥^G^H^Q^R^SU$nullÓ
// ^K^L^N^PWNS.keysZNS.objectsV$class¡^M<80>^B¡^O<80>^C<80>^DRoc^P Ò^T^U^V^WZ$classnameX$classes\NSDictionary¢^X^Y\NSDictionaryXNSObject_^P^ONSKeyedArchiverÑ^\^]Troot<80>^A^H^Q^Z#-27=CJR]dfhjlnqsx<83><8c><99><9c>©²ÄÇÌ^@^@^@^@^@^@^A^A^@^@^@^@^@^@^@^^^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@Î

//我们再用chenyu.txt归档IApple对象
IApple *apple = [[IApple alloc] initWithColor:@"red" weight:5.6 size:20];
IApple *apple1 = [[IApple alloc] initWithColor:@"wihte" weight:6.6 size:30];

//用NSKeyedArchiver进行IApple对象归档
[NSKeyedArchiver archiveRootObject:apple toFile:chenyuPath];
[NSKeyedArchiver archiveRootObject:apple1 toFile:chenyuPath];

IApple *saveApple = [NSKeyedUnarchiver unarchiveObjectWithFile:chenyuPath];
NSLog(@"saveApple is %@",saveApple);
}
}

4、运行结果
2018-07-22 00:08:57.804831+0800 cyTest[37026:15851965] document path:/Users/ls/Library/Developer/CoreSimulator/Devices/3FF9B833-FAF8-4C30-A855-3D40A4EAE8A6/data/Containers/Data/Application/272166E9-67BC-4E6B-B79A-0FF9DA389D7D/Documents
2018-07-22 00:08:57.810379+0800 cyTest[37026:15851965] make chenyu.txt success
2018-07-22 00:08:57.813994+0800 cyTest[37026:15851965] 123
2018-07-22 00:08:57.815001+0800 cyTest[37026:15851965] oc value is 10
2018-07-22 00:08:57.815228+0800 cyTest[37026:15851965] java value is 20
2018-07-22 00:08:57.815438+0800 cyTest[37026:15851965] c++ value is 30
2018-07-22 00:08:57.822014+0800 cyTest[37026:15851965] saveApple is <IApple [color = wihte,weight = 6.6,_size = 30]>

5、问题思考
是不是每次只能保持一个对象到文件里面呢?暂时感觉是这样的，后面遇到问题再分析。

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