转自: http://o0o0o0o.javaeye.com/blog/588889
//
// codeObj.h
// encodeObject
//
// Created by 110 on 10-2-6.
// Copyright 2010 __MyCompanyName__. All rights reserved.
//
#import <Cocoa/Cocoa.h<
/**
cocoa具备一种机制来将对象自身转换为某种格式并保存中磁盘上。
对象可以将它们的实例变量和其他数据编码为数据块，然后保存到磁盘中。以后将这些数据块都会到内存中，并且
还能基于保存的数据创建新对象。这个过程称为编码和解码，或称为序列化和反序列化。
*/
/**
要编码的对象，必须实现NSCoding协议。
@protocol NSCoding
-(void) encoderWithCoder:(NSCoder *) aCoder;
-(id) initWithCoder:(NSCoder *) aDecoder;
@end
当对象需要保存自身时－encoderWithCoder:方法被调用
当对象需要加载自身时－initWithCoder:方法被调用
*/
@interface codeObj : NSObject <NSCoding<{
NSString *name;
int magicNumber;
float shoseSize;
NSMutableArray *subThingies;
}
@property (copy) NSString *name;
@property int magicNumber;
@property float shoseSize;
@property (retain) NSMutableArray *subThingies;
-(id) initwithName:(NSString *) n
magicNumber:(int) mn shoseSize:(float) ss;
@end
// codeObj.m
// encodeObject
//
// Created by 110 on 10-2-6.
// Copyright 2010 __MyCompanyName__. All rights reserved.
//
#import "codeObj.h"
@implementation codeObj
@synthesize name;
@synthesize magicNumber;
@synthesize shoseSize;
@synthesize subThingies;
-(id) initwithName:(NSString *) n
magicNumber:(int) mn shoseSize:(float) ss{
if(self=[super init]){
self.name=n;
self.magicNumber=mn;
self.shoseSize=ss;
self.subThingies=[NSMutableArray array];
}
return (self);
}
-(void) dealloc{
[name release];
[subThingies release];
[super dealloc];
}
//nscoding协议的方法
-(void) encodeWithCoder:(NSCoder *) coder{
[coder encodeObject:name forKey:@"name"];
[coder encodeInt:magicNumber forKey:@"magicNumber"];
[coder encodeFloat:shoseSize forKey:@"shoseSize"];
[coder encodeObject:subThingies forKey:@"subThingies"];
}
/**
initWithCode:和其他init方法一样，中对对象执行操作之前，需要使用超类对它们进行初始化。为此，可以采用
两种方式，具体取决于父类，如果父类采用了NSCoding协议，则应该调用[super initWithCoder:decoder];
否则，只需要调用[super init]即可。NSObject不采用NSCoding协议，因此我们可以使用简单的init方法
*/
/**
decodeObjectForKey:把一个对象从解码器中取出
decodeIntForKey：把int从解码器中取出，在嵌入的对象上递归使用initWithCoder:方法。
*/
-(id) initWithCoder:(NSCoder *) decoder{
if(self =[super init]){
self.name=[decoder decodeObjectForKey:@"name"];
self.magicNumber=[decoder decodeIntForKey:@"magicNumber"];
self.shoseSize=[decoder decodeFloatForKey:@"shoseSize"];
self.subThingies=[decoder decodeObjectForKey:@"subThingies"];
}
return (self);
}
-(NSString *) description{
NSString *descripton=[NSString stringWithFormat:@"%@:%d,%.1f,%@",name,magicNumber,
shoseSize,subThingies];
return (descripton);
}
@end
<SPAN style="white-space: normal;"< <SPAN style="white-space: pre;"<#import <Foundation/Foundation.h<</SPAN<</SPAN<
<SPAN style="white-space: normal;"<</SPAN<#import "codeObj.h"
int main (int argc, const char * argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
codeObj *thing;
thing=[[[codeObj alloc] initwithName:@"name" magicNumber:20 shoseSize:30.5] autorelease];
NSLog(@"--------%@",thing);
/**
+archivedDataWithRootObject:类方法编码thing对象。首先，它在后台创建一个NSKeyedArchiver实例
，然后，它将NSKeyedArchiver实例传递给对象thing的－encodeWithCoder：方法。当thing编码自身的属性时
，它可能对其他对象也进行编码，例如字符串，数组以及我们可能输入到该数组中的任何内容。整个对象集合完成键和值
的编码后，具有键/值对的归档程序将所有对象扁平化为一个NSData类并将其返回.
*/
NSData *freezeDrid;
freezeDrid=[NSKeyedArchiver archivedDataWithRootObject:thing];
[freezeDrid writeToFile:@"/tmp/codeobj.txt" atomically:YES];
codeObj *anotherThing;
anotherThing=[[[codeObj alloc] initwithName:@"ssssss" magicNumber:20 shoseSize:4.5] autorelease];
[anotherThing.subThingies addObject:thing];
NSData *other;
other=[NSKeyedArchiver archivedDataWithRootObject:anotherThing];
//写入文件
[other writeToFile:@"/tmp/objandobj.txt" atomically:YES];
//从文件中读取
NSData *fileData;
fileData=[NSData dataWithContentsOfFile:@"/tmp/objandobj.txt"];
codeObj *fromFile;
fromFile=[NSKeyedUnarchiver unarchiveObjectWithData:fileData];
NSLog(@"------%@",fromFile);
[pool drain];
return 0;
}