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=@"[email protected]";
        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];
            
        }