【Objective-C】OC中自定义对象的归档基本概念和使用方法(实现NSCoding协议)

平时使用中，我们通常需要通过对自定义对象进行归档处理，自定义对象要进行归档,需要去实现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方法解码归档数据来进行初始化对象。

实现NSCoding协议后，就能通过NSKeyedArchiver进行归档

下面来看下例子代码:

Person.h头文件代码:

#import <Foundation/Foundation.h>

@interface Person : NSObject <NSCoding>
@property(nonatomic,copy)NSString *name;
@property(nonatomic,copy)NSString *email;
@property(nonatomic,copy)NSString *password;
@property(nonatomic,assign)int age;
@end

Person.m实现代码:

#import "Person.h"
#define AGE @"age"
#define NAME @"name"
#define EMAIL @"email"
#define PASSWORD @"password"
@implementation Person
//对对象属性进行编码方法
- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeInt:_age forKey:AGE];
    [aCoder encodeObject:_name forKey:NAME];
    [aCoder encodeObject:_email forKey:EMAIL];
    [aCoder encodeObject:_password forKey:PASSWORD];
}
//对对象属性进行解码方法
- (id)initWithCoder:(NSCoder *)aDecoder{
    self=[super init];
    if (self!=nil) {
        _age=[aDecoder decodeIntForKey:AGE];
        _name=[[aDecoder decodeObjectForKey:NAME]copy];
        _email=[[aDecoder decodeObjectForKey:EMAIL]copy];
        _password=[[aDecoder decodeObjectForKey:PASSWORD]copy];
        
    }
    return self;
}
-(void)dealloc{
    [_name release];
    [_email release];
    [_password release];
    [super dealloc];
}

main.m函数代码:

#import <Foundation/Foundation.h>
#import "Person.h"
int main(int argc, const char * argv[])
{

    @autoreleasepool {
        Person *person=[[Person alloc]init];
        person.name=@"jack";
        person.age=20;
        person.email=@"[email protected]";
        person.password=@"12345";
        NSString *homePath=NSHomeDirectory();
        NSString *srcPath=[homePath stringByAppendingPathComponent:@"Desktop/person.archiver"];
        BOOL success=[NSKeyedArchiver archiveRootObject:person toFile:srcPath];
        if (success) {
            NSLog(@"归档自定义对象成功.");
        }
        
        //还原数据
        Person *result= [NSKeyedUnarchiver unarchiveObjectWithFile:srcPath];
        NSLog(@"name=%@",result.name);
        NSLog(@"age=%d",result.age);
        NSLog(@"email=%@",result.email);
        NSLog(@"password=%@",result.password);
    }
    return 0;
}

运行截图: