有没有更好的方法将 JObject 转换为接口的任何实现？ [复制]

Question

我不确定是否有更好的方法来做到这一点。也许有人帮忙？

我想将JObject 类型的对象转换为工厂中的一个类。类本身应该根据另一个参数来决定。但我只能想到将对象序列化为字符串，然后再序列化回特定的类。一定有更好的方法吗？

https://dotnetfiddle.net/3Qwq6V

using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using System;

namespace Test
{
    public class Input
    {
        public int TypeId { get; set; }
        public object ObjectDefinesInput;
    }

    public class VoiceInput
    {
        public string Language;
    }

    public class TextInput
    {
        public string Encoding;
    }

    public interface IResponse
    {
        void Respond();
    }

    public class VoiceResponse : IResponse
    {
        private VoiceInput input { get; set; }
        public VoiceResponse(VoiceInput input) { this.input = input; }

        public void Respond()
        {
            // use information on VoiceInput to do something
            Console.WriteLine("(In "+ this.input.Language +"): beep buup boop.");
        }
    }

    public class TextResponse : IResponse
    {
        private TextInput input { get; set; }
        public TextResponse(TextInput input) { this.input = input; }
        public void Respond()
        {
            Console.WriteLine("I am a text handler. Using "+ this.input.Encoding +".");
        }
    }

    public static class ResponseFactory
    {
        public static IResponse CreateResponseHandler(Input input)
        {
            // ----------------- ISSUE HERE -----------------------------//
            // I'm using JsonConvert to serialize an <object> to a string, and then 

            string jsonObjectDefinesInput = JsonConvert.SerializeObject(input.ObjectDefinesInput, new JsonSerializerSettings
            {
                Formatting = Formatting.Indented,
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            });

            switch (input.TypeId)
            {
                case 1:
                    // (VoiceInput) input.ObjectDefinesInput throws exception
                    // input.ObjectDefinesInput as VoiceInput returns null
                    VoiceInput voiceInput = JsonConvert.DeserializeObject<VoiceInput>(jsonObjectDefinesInput);
                    return new VoiceResponse(voiceInput);
                default:
                    TextInput textInput = JsonConvert.DeserializeObject<TextInput>(jsonObjectDefinesInput);
                    return new TextResponse(textInput);
            }
        }
    }

    public class Program
    {
        public static void Main(string[] args)
        {
            string jsonData1 = "{ \"typeId\": 1, \"ObjectDefinesInput\": { \"Language\": \"Robot\" } }";
            string jsonData2 = "{ \"typeId\": 2, \"ObjectDefinesInput\": { \"Encoding\": \"UTF-8\" } }";

            Input someInpput1 = JsonConvert.DeserializeObject<Input>(jsonData1);
            Input someInpput2 = JsonConvert.DeserializeObject<Input>(jsonData2);

            IResponse testResponse1 = ResponseFactory.CreateResponseHandler(someInpput1);
            IResponse testResponse2 = ResponseFactory.CreateResponseHandler(someInpput2);

            testResponse1.Respond();

            testResponse2.Respond();

            Console.ReadLine();
        }
    }
}

Answer 1

如果你只是提供了正确的输入，你可以转换它们：

var voiceInput = new Input()
{
    TypeId = 1,
    ObjectDefinesInput = new VoiceInput(){ ... }
}

和

switch (input.TypeId)
{
    case 1:
          VoiceInput voiceInput = (VoiceInput)input.ObjectDefinesInput;
          return new VoiceResponse(voiceInput);
    default:
          TextInput textInput = (textInput)input.ObjectDefinesInput;
          return new TextResponse(textInput );
}

如果您想要某种类型安全，请让您的 Input 类具有输入类型的泛型类型参数

public class Input<T>
{
    public int TypeId { get; set; }
    public T ObjectDefinesInput;
}

还有

var voiceInput = new Input<VoiceInput>()
{
    TypeId = 1,
    ObjectDefinesInput = new VoiceInput(){ ... }
}

那么不需要强制转换：

switch (input.TypeId)
{
    case 1:
          return new VoiceResponse(input.ObjectDefinesInput);
    default:
          return new TextResponse(input.ObjectDefinesInput);
}

Answer 2

嗯，因为我发现类型其实是JObject（我反序列化成

input.ObjectDefinesInput.ToObject<TextInput>();

根据Converting a JToken (or string) to a given Type