objective-c 自定义归档

基本概念

　　自定义对象要支持归档，需要实现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

　　实现NSCoding协议后，就能通过NSKeyedArchiver归档

 

实例代码：

User.h

#import <Foundation/Foundation.h>

@interface User : NSObject<NSCoding>

@property(nonatomic,copy)NSString *name;
@property(nonatomic,copy)NSString *email;
@property(nonatomic,assign)NSInteger age;

@end

User.m

#import "User.h"
#define AGE @"age"
#define NAME @"name"
#define EMAIL @"email"
@implementation User

//对属性编码，归档时调用
- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeInteger:_age forKey:AGE];
    [aCoder encodeObject:_name forKey:NAME];
    [aCoder encodeObject:_email forKey:EMAIL];
    
}

//对属性解码，解归档时调用
- (id)initWithCoder:(NSCoder *)aDecoder{
    if (self = [super init]) {
        _age = [aDecoder decodeIntegerForKey:AGE];
        self.name = [aDecoder decodeObjectForKey:NAME];
        self.email = [aDecoder decodeObjectForKey:EMAIL];
    }
    return self;
}


@end

main.m

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

    @autoreleasepool {
        
        // insert code here...
        NSLog(@"Hello, World!");
        //归档
//        User *user = [[User alloc] init];
//        user.name = @"Warlock";
//        user.email = @"warlock@wow.com";
//        user.age = 1;
//        
//        NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"user.txt"];
//        if ([NSKeyedArchiver archiveRootObject:user toFile:path]){
//            NSLog(@"创建成功");
//        }
        
        //解归档
        NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"user.txt"];
        User *user = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
        NSLog(@"%@",user.name);
        
    }
    return 0;
}

先将  解归档  注释起来，运行归档，     然后注释 归档  ，在运行解归档