swift - Swift 可以将类/结构数据转换为字典吗？

Question

例如:

class Test {
    var name: String;
    var age: Int;
    var height: Double;
    func convertToDict() -> [String: AnyObject] { ..... }
}

let test = Test();
test.name = "Alex";
test.age = 30;
test.height = 170;

let dict = test.convertToDict();

dict 将包含内容:

{"name": "Alex", "age": 30, height: 170}

这在 Swift 中可能吗？

我可以访问像字典这样的类吗，例如可能使用:

test.value(forKey: "name");

或者类似的东西？

Answer 1

您只需将计算属性添加到您的 struct 以返回包含您的值的 Dictionary。请注意，Swift 原生字典类型没有任何名为 value(forKey:) 的方法。您需要将 Dictionary 转换为 NSDictionary:

struct Test {
    let name: String
    let age: Int
    let height: Double
    var dictionary: [String: Any] {
        return ["name": name,
                "age": age,
                "height": height]
    }
    var nsDictionary: NSDictionary {
        return dictionary as NSDictionary
    }
}

---

您还可以按照@ColGraff 发布的链接答案中的建议扩展Encodable 协议(protocol)，使其对所有Encodable 结构通用:

struct JSON {
    static let encoder = JSONEncoder()
}
extension Encodable {
    subscript(key: String) -> Any? {
        return dictionary[key]
    }
    var dictionary: [String: Any] {
        return (try? JSONSerialization.jsonObject(with: JSON.encoder.encode(self))) as? [String: Any] ?? [:]
    }
}

---

struct Test: Codable {
    let name: String
    let age: Int
    let height: Double
}

let test = Test(name: "Alex", age: 30, height: 170)
test["name"]    // Alex
test["age"]     // 30
test["height"]  // 170