Question

我试图让一个快速的3结构符合_ObjectiveCBridgeable，但我不确定我还需要什么来满足协议。下面是我的结构和_ObjectiveCBridgeable一致性。我错过了一些东西，但我不确定它是什么。

struct Box {
    let contents: Any
}

extension Box: _ObjectiveCBridgeable {
    typealias _ObjectiveCType = thing;

    init(fromObjectiveC source: _ObjectiveCType) {
        contents = source.contents
    }

    static func _isBridgedToObjectiveC() -> Bool {
        return true
    }
    static func _getObjectiveCType() -> Any.Type {
        return _ObjectiveCType.self
    }
    func _bridgeToObjectiveC() -> Box._ObjectiveCType {
        return thing(contents: self.contents)
    }

    static func _forceBridgeFromObjectiveC(_ source: Box._ObjectiveCType, result: inout Box?) {
        result = Box(contents: source.contents)
    }

    static func _conditionallyBridgeFromObjectiveC(_ source: Box._ObjectiveCType, result: inout Box?) -> Bool {
        _forceBridgeFromObjectiveC(source, result: &result)
        return true
    }
}

// Objc

@interface thing : NSObject
@property (readonly) id contents;
-(instancetype)initWithContents:(id)contents;
@end
@implementation thing
- (instancetype)initWithContents:(id)contents {
    if ((self = [super init])) {
        _contents = contents;
    }
    return self;
}
@end

Answer 1

正如下划线所示，_ObjectiveCBridgeable是私密的。其目的是“满足将Objective-C对象类型桥接到Swift值类型的特定需求”。你不能为自己的类型采用它;它通过“引擎盖下的编译器魔法”工作。

有proposal on the table提供公开版本，但尚未实施。

swift 3 _ObjectiveCBridgeable一致性

1 个答案: