iOS 归档存储

归档

• 1.1. 简单归档：指把简单的字符串、数组等对象进行归档

    // 初始化需要归档的数组
    NSArray *array = @[@"a", @"b", @"c"];
    // 创建归档文件存储路径
    NSString *path = PATH_AT_Tmp(@"file.archive"); // 文件后缀随意
    // 归档
    [NSKeyedArchiver archiveRootObject:array toFile:path];
    // 解归档
    NSArray *tempArray = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
    // 输出打印
    NSLog(@"kkk --- %@", tempArray);

• 1.2. data归档：先新建一个可变的data对象，然后通过创建一个NSKeyedArchiver实例对象对各种类型的数据进行归档到data的归档文件中

    // 创建归档文件存储路径
    NSString *path = PATH_AT_Tmp(@"file.archive");
    // 创建可变data
    NSMutableData *data = [NSMutableData data];
    // 创建归档实例
    NSKeyedArchiver *keyArch = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    // 归档
    [keyArch encodeObject:@"勇往直前" forKey:@"name"];
    [keyArch encodeInteger:18 forKey:@"age"];
    [keyArch finishEncoding];
    [data writeToFile:path atomically:YES];

    // 解归档
    NSData *outData = [NSData dataWithContentsOfFile:path];
    NSKeyedUnarchiver *keyUnarch = [[NSKeyedUnarchiver alloc] initForReadingWithData:outData];
    NSString *name = [keyUnarch decodeObjectForKey:@"name"];
    NSInteger age = [keyUnarch decodeIntegerForKey:@"age"];
    NSLog(@"name: %@, age: %ld", name, (long)age);

• 1.3. 自定义归档
  定义一个类UserInfoModel，需遵守NSCoding协议

UserInfoModel.h文件中定义name、age和sex三个属性
#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface UserInfoModel : NSObject<NSCoding>

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

@end

NS_ASSUME_NONNULL_END

UserInfoModel.m文件需要重写一个归档方法、一个解归档方法
#import "UserInfoModel.h"

@implementation UserInfoModel

// 重写归档方法，把调用者的属性进行归档
- (void)encodeWithCoder:(NSCoder *)coder
{
    [coder encodeObject:self.name forKey:@"name"];
    [coder encodeInteger:self.age forKey:@"age"];
    [coder encodeObject:self.sex forKey:@"sex"];
}

// 重写解归档方法，把属性赋值给新对象的对应属性
- (instancetype)initWithCoder:(NSCoder *)coder
{
    self = [super init];
    if (self) {
        self.name = [coder decodeObjectForKey:@"name"];
        self.age = [coder decodeIntegerForKey:@"age"];
        self.sex = [coder decodeObjectForKey:@"sex"];
    }
    return self;
}

@end

• 1.3.1归档与解归档的应用

// 初始化对象
UserInfoModel *model = [[UserInfoModel alloc] init];
model.name = @"遇见";
model.age = 18;
model.sex = @"Man";

// 创建归档文件存储路径
NSString *path = PATH_AT_Tmp(@"file.archive");
// 归档
[NSKeyedArchiver archiveRootObject:model toFile:path];
// 解归档
UserInfoModel *outModel = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
// 输出
NSLog(@"name: %@, age: %ld, sex: %@", outModel.name, (long)outModel.age, outModel.sex);

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