包含自定义对象的NSMutableDictionaries的NSCoding

Question

我试图序列化SearchEntity对象(自定义对象)含有NSMutableDictionary含一组类型的CategoryEntity(自定义对象).

1 SearchEntity<NSCoding>包含:1 NSMutableDictionary(参数)参数,包含X CategoryEntities<NSCoding>只包含字符串和数字.

在这条线[encoder encodeObject:parameters forKey:kPreviousSearchEntityKey];的SearchEntity encodeWithCoder"我得到GDB:中断每一次,没有错误消息,异常等只是GDB:中断.

这是SearchEntity和参数的实现NSMutableDictionary

#pragma mark -
#pragma mark NSCoding delegate methods

- (void) encodeWithCoder:(NSCoder*)encoder 
{
    //encode all the values so they can be persisted in NSUserdefaults
    if (parameters) 
        [encoder encodeObject:parameters forKey:kPreviousSearchEntityKey]; //GDB:Interrupted!
}

- (id) initWithCoder:(NSCoder*)decoder 
{
    if (self = [super init]) 
    {
        //decode all values to return an object from NSUserdefaults in the same state as when saved     
        [self setParameters:[decoder decodeObjectForKey:kPreviousSearchEntityKey]];
    }
    return self;
}

该CategoryEntity还实现NSCoding协议,看起来像这样:

- (void) encodeWithCoder:(NSCoder*)encoder 
{
    //encode all the values so they can be persisted in NSUserdefaults
    [encoder encodeObject:ID forKey:kIDKey];
    [encoder encodeObject:text forKey:kTextKey];
    [encoder encodeObject:category forKey:kCategoryKey];
    [encoder encodeObject:categoryIdentifierKey forKey:kCategoryIdentifierKey];
}

- (id) initWithCoder:(NSCoder*)decoder 
{
    if (self = [super init]) {

        //decode all values to return an object from NSUserdefaults in the same state as when saved
        [self setID:[decoder decodeObjectForKey:kIDKey]];
        [self setText:[decoder decodeObjectForKey:kTextKey]];
        [self setCategory:[decoder decodeObjectForKey:kCategoryKey]];
        [self setCategoryIdentifierKey:[decoder decodeObjectForKey:kCategoryIdentifierKey]];
    }
    return self;
}

我尝试从NSUserDefaults的对,像这样的包装进行编码:

+ (void) setPreviousSearchParameters:(SearchParameterEntity*) entity
{
    if (entity) 
    {
        //first encode the entity (implements the NSCoding protocol) then save it
        NSData *encodedObject = [NSKeyedArchiver archivedDataWithRootObject:entity];
        [[self defaults] setObject:encodedObject forKey:kPreviousSearchKey];
        [[self defaults] synchronize];      
    }
}

+ (SearchParameterEntity*) getPreviousSearchParameters
{
    //retrieve the encoded NSData object that was saved, decode and return it
    SearchParameterEntity *entity = nil;
    NSData *encodedObject = [[self defaults] objectForKey:kPreviousSearchKey];

    if (encodedObject)
        entity = [NSKeyedUnarchiver unarchiveObjectWithData:encodedObject];

    return entity;
}

我在想,当我问到序列化SearchEntity,它将开始连载的"参数" mutableDictionary对象,NSCoder将调用包含在字典中的CategoryEntities"编码",他们都将与他们的正确编码的对象作出回应.

但是我只是得到了GDB:在控制台的底部中断了.

我该怎么调试呢？

而且是我的方法不对,我应该在包装NSData的编码的各个层面？

PS.我使用ResultEntity包含NSArrays 的完全相同的东西CategoryEntities,它编码没有问题,所以我想NSMutableDictionary是唯一突出的东西.

Answer 1

使用 NSKeyedArchiver 归档对象的问题是无法对可变对象进行编码。仅NSArray、NSDictionary、NSString、NSDate、NSNumber和NSData（及其一些子类）的实例可以被序列化

因此，在您的 SearchEntity 方法中，encodeWithCoder:您应该尝试从 NSMutableDictionary 创建 NSDictionary，然后对不可变的进行编码：

if (parameters) {
    NSDictionary *dict = [NSDictionary dictionaryWithDictionary:parameters];
    [encoder encodeObject:dict forKey:kPreviousSearchEntityKey];
}

另外，在initWithCoder:方法中尝试从编码的不可变字典创建 NSMutableDictionary：

NSDictionary *dict = [decoder decodeObjectForKey:kPreviousSearchEntityKey];
     [self setParameters:[NSMutableDictionary dictionaryWithDictionary:dict]];

还要检查parameters字典中的所有对象是否符合 NSCoding 协议，并确保所有对象在其encodeWithCoder:方法中仅编码不可变对象。

希望它能解决问题。