ios - 如何编码/解码具有自定义对象数组的自定义对象？

Question

我有一个自定义对象，它有一个 property 和另一组自定义 NSDictionary 对象的 NSArray。当我对数组进行编码和解码时，NSDictionary 对象在应该具有值时却为空。我读过的所有内容都说 NSArray 对象符合 NSCoding，但我觉得我必须做更多的事情才能正确编码 NSDictionary NSArray 中的对象...我错过了什么？

@interface Game : NSObject <NSMutableCopying, NSCoding>
@property int rows;
@property int cols;
@property NSMutableArray *troughs;

- (void)encodeWithCoder:(NSCoder *)encoder {

    // encoding properties
    [encoder encodeInteger:rows forKey:@"rows"];
    [encoder encodeInteger:cols forKey:@"cols"];
    [encoder encodeObject:troughs forKey:@"troughs"];
}

- (id)initWithCoder:(NSCoder *)coder {
    self = [super init];
    if (self) {
        rows = (int)[coder decodeIntegerForKey:@"rows"];
        cols = (int)[coder decodeIntegerForKey:@"cols"];
        troughs = [coder decodeObjectForKey:@"troughs"];
    }
    return self;
}

槽数组包含定义为的对象:

@interface Trough : NSDictionary <NSMutableCopying, NSCoding>
@property int col;
@property int row;
@property BOOL isLocked;
@property NSMutableArray *tokens;

- (void)encodeWithCoder:(NSCoder *)encoder {
    // encoding properties
    [encoder encodeInteger:col forKey:@"col"];
    [encoder encodeInteger:row forKey:@"row"];
    [encoder encodeBool:isLocked forKey:@"isLocked"];
    [encoder encodeObject:tokens forKey:@"tokens"];
}

- (id)initWithCoder:(NSCoder *)coder {
    self = [super init];
    if (self) {
        col = (int)[coder decodeIntegerForKey:@"col"];
        row = (int)[coder decodeIntegerForKey:@"row"];
        isLocked = [coder decodeBoolForKey:@"isLocked"];
        tokens = [coder decodeObjectForKey:@"tokens"];
    }
    return self;
}

Answer 1

子类化 NSDictionary 非常不寻常。如果这些 NSCopying 实现有任何工作的机会，它们也需要调用继承的行为。

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [super encodeWithCoder:aCoder];
    // encode your Trough properties
}

- (id)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        // decode your trough properties
    }
    return self;
}