iOS 歸檔解檔的使用

  • 利用OC提供的解歸檔來實(shí)現(xiàn)自定義模型緩存,這里模型遵循<NSSecureCoding>協(xié)議。
  • <NSSecureCoding>基于<NSCoding>,相對更加安全。
方案一:(常規(guī)寫法:字段比較多的話,一個一個編解碼比較麻煩)
Person.h文件
@interface Person : NSObject <NSSecureCoding>  //解歸檔需要遵循NSSecureCoding協(xié)議,并實(shí)現(xiàn)相關(guān)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"];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        self.name = [aDecoder decodeObjectForKey:@"name"];
        self.sex = [aDecoder decodeIntegerForKey:@"sex"];
        self.age = [aDecoder decodeIntegerForKey:@"age"];
    }
    return self;
}

+ (BOOL)supportsSecureCoding {
    return YES;
}

@end
方案二:(利用YYModel處理編解碼)
Person.h文件
@interface Person : NSObject <NSSecureCoding>  //解歸檔需要遵循NSSecureCoding協(xié)議,并實(shí)現(xiàn)相關(guān)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 {
    [self yy_modelEncodeWithCoder:aCoder];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super init];
    return [self yy_modelInitWithCoder:aDecoder];
}

+ (BOOL)supportsSecureCoding {
    return YES;
}

@end
方案三:(利用runtime處理編解碼,要導(dǎo)入頭文件#import <objc/runtime.h>
Person.h文件
@interface Person : NSObject <NSSecureCoding>  //解歸檔需要遵循NSSecureCoding協(xié)議,并實(shí)現(xiàn)相關(guān)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 {
    unsigned int count = 0;
    // 獲取所有實(shí)例變量
    Ivar *ivars = class_copyIvarList([self class], &count);
   // 遍歷所有實(shí)例變量
    for (int i = 0; i < count; i++) {
        Ivar ivar = ivars[I];
        // 獲取實(shí)例變量名
        const char *name = ivar_getName(ivar);
        NSString *key = [NSString stringWithUTF8String:name];
        // 通過KVC獲取value值
        id value = [self valueForKey:key];
        // 編碼
        [coder encodeObject:value forKey:key];
    }
    free(ivars); // C不會自動釋放,需要手動釋放。
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        unsigned int count = 0;
        // 獲取所有實(shí)例變量
        Ivar *ivars = class_copyIvarList([self class], &count);
        // 遍歷所有實(shí)例變量
        for (int i = 0; i < count; i++) {
            Ivar ivar = ivars[i];
            // 獲取實(shí)例變量名
            const char *name = ivar_getName(ivar);
            NSString *key = [NSString stringWithUTF8String:name];
            // 解碼
            id value = [coder decodeObjectOfClass:[self class] forKey:key];
            // 通過KVC 設(shè)置value
            [self setValue:value forKey:key];
        }
        free(ivars); // C不會自動釋放,需要手動釋放。
    }
    return self;
}

+ (BOOL)supportsSecureCoding {
    return YES;
}

@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];
    
    // 這里以緩存模型數(shù)組為例,緩存單個模型對象,直接把對應(yīng)模型數(shù)組參數(shù)改為模型對象即可(存取都要更改)
    [self wirteToFile: personArr]; // 歸檔
    [self readFromFile]; // 解檔
}

// 歸檔
- (void)wirteToFile:(NSArray *)dataArray {
    NSString *fileName = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).lastObject stringByAppendingPathComponent:@"archive.person"];
    if (@available(iOS 11.0, *)) {
        NSData *arrayData = [NSKeyedArchiver archivedDataWithRootObject:dataArray requiringSecureCoding:YES error:nil];
        [arrayData writeToFile:fileName atomically:YES];
    } else {
        NSData *arrayData = [NSKeyedArchiver archivedDataWithRootObject:dataArray];
        [arrayData writeToFile:fileName atomically:YES];
    }
}

// 解檔
- (void)readFromFile {
    NSString *fileName = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).lastObject stringByAppendingPathComponent:@"archive.person"];
    NSData *resultData = [[NSData alloc]initWithContentsOfFile:fileName];
    //  解檔模型數(shù)組使用unarchivedArrayOfObjectsOfClass: fromData: error: 此方法iOS 14.0可用
    // 解檔單個模型數(shù)據(jù)可以使用 unarchivedObjectOfClass: fromData: error:,iOS 11.0可用
    if (@available(iOS 14.0, *)) {
        NSArray *resultArray = [NSKeyedUnarchiver unarchivedArrayOfObjectsOfClass:[Person class] fromData:resultData error:nil];
        NSLog(@"%@",resultArray);
    } else {
        NSArray *resultArray = [NSKeyedUnarchiver unarchiveObjectWithData:resultData];
        NSLog(@"%@",resultArray);
    }
}

@end
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