iOS 归档、解档之缓存自定义模型

• 不管是NSUserDefaults 或者是 plist都不能对自定义的对象进行存储, 这里可以利用OC提供的解归档来实现，注意自定义模型要遵循<NSCoding>协议。

Person.h文件

@interface Person : NSObject <NSCoding>  //解归档需要遵循NSCoding协议，并实现相关方法

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

@end

Person.m文件

@implementation Person

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeInteger:self.sex forKey:@"sex"];
    [aCoder encodeInteger:self.age forKey:@"age"];

    // 若项目中使用了第三方YYModel，可直接使用下面这句代码
//    [self yy_modelEncodeWithCoder:aCoder];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        self.name = [aDecoder decodeObjectForKey:@"name"];
        self.sex = [aDecoder decodeIntegerForKey:@"sex"];
        self.age = [aDecoder decodeIntegerForKey:@"age"];
        
        // 若项目中使用了第三方YYModel，可直接使用下面这句代码
//        [self yy_modelInitWithCoder:aDecoder];
    }
    return self;
}

@end

ViewController.m文件

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    Person *person1 = [Person new];
    person1.name = @"程序猿";
    person1.sex = 1;
    person1.age = 26;
    
    Person *person2 = [Person new];
    person2.name = @"程序媛";
    person2.sex = 0;
    person2.age = 27;
    
    NSMutableArray *personArr = [NSMutableArray arrayWithCapacity:0];
    [personArr addObject:person1];
    [personArr addObject:person2];
    
    // 这里以缓存模型数组为例，缓存单个模型对象，直接把对应模型数组参数给为模型对象即可（存取都要更改）
    [self wirteToFile: personArr]; // 归档
    [self readFromFile]; // 解档
}

// 归档
- (void)wirteToFile:(NSArray *)dataArray {
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *document = [documentPaths lastObject];
    NSString *documentPath = [document stringByAppendingPathComponent:@"person"];
    NSData *arrayData = [NSKeyedArchiver archivedDataWithRootObject:dataArray];
    if ([arrayData writeToFile:documentPath atomically:YES]) { // 此行代码必须写，否则归档不成功
        NSLog(@"归档成功");
    }
}

// 解档
- (void)readFromFile {
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *document = [documentPaths lastObject];
    NSString *documentPath = [document stringByAppendingPathComponent:@"person"];
    NSData *resultData = [NSData dataWithContentsOfFile:documentPath];
    NSArray *resultArray = [NSKeyedUnarchiver unarchiveObjectWithData:resultData];
    NSLog(@"%@",resultArray);
}

@end