一、归档 保存model

//Person是model 
Person *p = [Person new];
p.age = 18;
p.name = @"小明";

//放到temp
NSString *temp = NSTemporaryDirectory();
NSString *filePath = [temp stringByAppendingString:@"h.h"];

//归档--存储
[NSKeyedArchiver archiveRootObject:p toFile:filePath];

//🐷解档

NSString *temp = NSTemporaryDirectory();
NSString *filePath = [temp stringByAppendingString:@"h.h"];

Person * p = [NSKeyedUnarchiver unarchiveObjectWithFile:filePath];

NSLog(@"%@今年%d岁了",p.name,p.age);

二、NSUserDefaults 本地存储model

Person *p = [Person new];
p.age = 18;
p.name = @"小明";
//将student类型变为NSData类型，保存
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:p];
DEF_PERSISTENT_SET_OBJECT(data, @"Person");

//取model
Person *person = [NSKeyedUnarchiver unarchiveObjectWithData:DEF_PERSISTENT_GET_OBJECT(@"Person")];
NSLog(@"%@今年%d岁了",person.name,person.age);

Person类

//Person.h Person是直接继承自NSObject,没有实现copyWithZone（Person实例对象copy会报错）
#import <Foundation/Foundation.h>

@interface Person : NSObject<NSCoding>

/** 年龄 **/
@property (nonatomic,assign) int age;

/** 名字 **/
@property (nonatomic,copy) NSString* name;

@end

//Person.m
//当外面归档这个对象的时候，就会调用这个方法，如果不实现就会报错！！
- (void)encodeWithCoder:(NSCoder *)coder
{
//    [coder encodeObject:_name forKey:@"name"];
//    [coder encodeInt:_age forKey:@"age"];
    
    
    //利用Runtime来归档
    unsigned int count = 0;
    //C语言里面，如果传基本数据类型的指针！那么都是需要在函数内部改变它的值
    Ivar *ivars = class_copyIvarList([Person class], &count);
//    NSLog(@"%d",count);//.m照样能够拿到
    
    for (int i = 0; i< count; i++) {
        
        Ivar ivar = ivars[i];
        const char *name = ivar_getName(ivar);
//        NSLog(@"%s",name);
        
        NSString *key = [NSString stringWithUTF8String:name];
        //属性的值！！KVC 哥们给我一个名称，我就能拿到一个值
        
        [coder encodeObject:[self valueForKey:key] forKey:key];
    }
    
    //在C语言里面，但凡看到new，create，copy函数需要释放指针！！
    free(ivars);
}

 - (instancetype)initWithCoder:(NSCoder *)coder
{
    self = [super init];
    if (self) {
//        //写解档的代码
//        _name = [coder decodeObjectForKey:@"name"];
//        _age = [coder decodeIntForKey:@"age"];
        
        //利用Runtime来解档
        unsigned int count = 0;
        //C语言里面，如果传基本数据类型的指针！那么都是需要在函数内部改变它的值
        Ivar *ivars = class_copyIvarList([Person class], &count);
//        NSLog(@"%d",count);//.m照样能够拿到
        
        for (int i = 0; i< count; i++) {
            
            Ivar ivar = ivars[i];
            const char *name = ivar_getName(ivar);
            //        NSLog(@"%s",name);
            
            NSString *key = [NSString stringWithUTF8String:name];
            //解档
            id value = [coder decodeObjectForKey:key];
            //利用KVC 设置
            [self setValue:value forKey:key];
            
        }
        
        free(ivars);
    }
    return self;
}

声明的宏

/**
 *    永久存储对象
 *
 *  NSUserDefaults保存的文件在tmp文件夹里
 *
 *    @param    object      需存储的对象
 *    @param    key         对应的key
 */
#define DEF_PERSISTENT_SET_OBJECT(object, key)                                                                                                 \
({                                                                                                                                             \
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];                                                                          \
[defaults setObject:object forKey:key];                                                                                                    \
[defaults synchronize];                                                                                                                    \
})

/**
 *    取出永久存储的对象
 *
 *    @param    key     所需对象对应的key
 *    @return    key     所对应的对象
 */
#define DEF_PERSISTENT_GET_OBJECT(key)  [[NSUserDefaults standardUserDefaults] objectForKey:key]

推荐一篇文章，写的很好。
编程小翁：https://www.jianshu.com/p/fed1dcb1ac9f?utm_campaign=hugo&utm_medium=reader_share&utm_content=note&utm_source=weixin-friends