自定义对象要实现归档必须实现NSCoding协议

NSCoding协议有两个方法，encodeWithCoder方法对对象的属性数据做编码处理，initWithCoder解码归档数据来初始化对象。

#import <Foundation/Foundation.h>

@interface user : NSObject <NSCoding>

@property(nonatomic,retain)NSString *name;

@property(nonatomic,retain)NSString *email;

@property(nonatomic,retain)NSString *pwd;

@property(nonatomic,assign)int age;

@end

#import "user.h"

#define AGE @"age"

#define NAME @"name"

#define EMAIL @"email"

#define PASSWORD @"password"

@implementation user

//对属性编码

- (void)encodeWithCoder:(NSCoder *)aCoder

{

[aCoder encodeInt:_ageforKey:@"age"];

[aCoder encodeObject:_nameforKey:AGE];

[aCoder encodeObject:_emailforKey:EMAIL];

[aCoder encodeObject:_pwdforKey:PASSWORD];

}

//对属性解码

- (id)initWithCoder:(NSCoder *)aDecoder

{

self=[super init];

if(self)

{

self.age=[aDecoderdecodeIntForKey:AGE];

self.name=[aDecoderdecodeObjectForKey:NAME];

self.email=[aDecoderdecodeObjectForKey:EMAIL];

self.pwd=[aDecoderdecodeObjectForKey:PASSWORD];

}

returnself;

}

-(void)dealloc

{

[_name release];

[_email release];

[_pwd release];

[super dealloc];

}

@end

main函数的调用

    user *userObj=[[user alloc] init];

        userObj.age=33;

        userObj.email=@"adfdadf@qq.com";

        userObj.pwd=@"212212";

        userObj.name=@"ricard";

        NSString *path=[NSHomeDirectory() stringByAppendingPathComponent:@"Desktop/custom.text"];

        BOOL succ=[NSKeyedArchiver archiveRootObject:userObj toFile:path];

        if (succ) {

                    NSLog(@"Hello, World!");

            user *usertemp=[NSKeyedUnarchiver unarchiveObjectWithFile:path];

        }