Json.NET:反序列化嵌套字典

Question

将对象反序列化为Dictionary(JsonConvert.DeserializeObject<IDictionary<string,object>>(json))嵌套对象时,将其反序列化为JObjects.是否可以强制嵌套对象反序列化为Dictionarys？

Answer 1

我找到了一种Dictionary<string,object>通过提供CustomCreationConverter实现来转换所有嵌套对象的方法:

class MyConverter : CustomCreationConverter<IDictionary<string, object>>
{
    public override IDictionary<string, object> Create(Type objectType)
    {
        return new Dictionary<string, object>();
    }

    public override bool CanConvert(Type objectType)
    {
        // in addition to handling IDictionary<string, object>
        // we want to handle the deserialization of dict value
        // which is of type object
        return objectType == typeof(object) || base.CanConvert(objectType);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.StartObject
            || reader.TokenType == JsonToken.Null)
            return base.ReadJson(reader, objectType, existingValue, serializer);

        // if the next token is not an object
        // then fall back on standard deserializer (strings, numbers etc.)
        return serializer.Deserialize(reader);
    }
}

class Program
{
    static void Main(string[] args)
    {
        var json = File.ReadAllText(@"c:\test.json");
        var obj = JsonConvert.DeserializeObject<IDictionary<string, object>>(
            json, new JsonConverter[] {new MyConverter()});
    }
}

文档:带有Json.NET的CustomCreationConverter

Answer 2

当我遇到这个问题时，我有一个非常相似但稍微复杂的需求。起初我想也许我可以调整接受的答案，但这似乎有点复杂，我最终采取了不同的方法。我试图在传统的 C++ API 之上放置一个现代 JSON 层。我会省去你的细节，只是说要求归结为：

• JSON 对象变为Dictionary<string,object>.

• JSON 数组变为List<object>.

• JSON 值成为相应的原始 CLR 值。

• 对象和数组可以无限嵌套。

我首先将请求字符串反序列化为Newtonsoft JSON对象，然后调用我的方法按照上述要求进行转换：

var jsonObject = JsonConvert.DeserializeObject(requestString);
var apiRequest = ToApiRequest(jsonObject);
// call the legacy C++ API ...

这是我转换为 API 期望结构的方法：

    private static object ToApiRequest(object requestObject)
    {
        switch (requestObject)
        {
            case JObject jObject: // objects become Dictionary<string,object>
                return ((IEnumerable<KeyValuePair<string, JToken>>) jObject).ToDictionary(j => j.Key, j => ToApiRequest(j.Value));
            case JArray jArray: // arrays become List<object>
                return jArray.Select(ToApiRequest).ToList();
            case JValue jValue: // values just become the value
                return jValue.Value;
            default: // don't know what to do here
                throw new Exception($"Unsupported type: {requestObject.GetType()}");
        }
    }

我希望有人能发现这种方法很有用。