使用 NewtonSoft 反序列化 JSon 子对象

Question

I am new to NewtonSoft and trying to deserialize an object, containing a subobect but I'm getting a null object in my subobject when deserializing...

My Json is:

"{\"id\":\"5e6106600066d227a231ceb8\",\"complete\":null,\"questions\":{\"5e60af61a7be775b0d31ea77\":{\"timeStamp\":\"2020-03-05T15:01:56.000000Z\",\"choices\":[\"dsbb\"]},\"5e60af66a7be775b0d31ea78\":{\"timeStamp\":\"2020-03-05T15:02:02.000000Z\",\"choices\":[\"9999999999\"]},\"5e60af76dd15333d1727ce09\":{\"timeStamp\":\"2020-03-05T15:02:11.000000Z\",\"choices\":[\"lj@test.com\"]},\"5e60afeeb406ed608058d045\":{\"timeStamp\":\"2020-03-05T15:02:15.000000Z\",\"choices\":[0]},\"5e5d282331808f44ce4b0b76\":{\"timeStamp\":\"2020-03-05T15:02:22.000000Z\",\"choices\":[0]},\"5e5cec17ae23a40b0c645614\":{\"timeStamp\":\"2020-03-05T15:02:29.000000Z\",\"choices\":[0]},\"5e5d08d235bf95782b049cb3\":{\"timeStamp\":\"2020-03-05T15:02:34.000000Z\",\"choices\":[2]},\"5e5d0a05a0be6b6533195f17\":{\"timeStamp\":\"2020-03-05T15:02:43.000000Z\",\"choices\":[0]},\"5e5cecdcf3c27f611b3df2fa\":{\"timeStamp\":\"2020-03-05T15:03:01.000000Z\",\"choices\":[\"100\"]},\"5e5cedd7949da059190f2146\":{\"timeStamp\":\"2020-03-05T15:03:10.000000Z\",\"choices\":[1,3,4]},\"5e60e8e899017615e27ad107\":{\"timeStamp\":\"2020-03-05T15:03:15.000000Z\",\"choices\":[0]},\"5e60e95d479b812cb4777b2f\":{\"timeStamp\":\"2020-03-05T15:03:22.000000Z\",\"choices\":[0]},\"5e60e9feff05631d3b0585d8\":{\"timeStamp\":\"2020-03-05T15:03:59.000000Z\",\"choices\":[\"fveg\"]}},\"ip_address\":\"188.165.111.130\",\"created_at\":\"2020-03-05T14:02:08.621000Z\",\"updated_at\":\"2020-03-05T14:04:21.995000Z\"}"

my object definitions is:

public class Respondant
{
    [JsonProperty("id")]
    public string Id { get; set; }

    [JsonProperty("ip_address")]
    public string IpAddress { get; set; }

    [JsonProperty("created_at")]
    public DateTimeOffset CreatedAt { get; set; }

    [JsonProperty("questions")]
    public Questions Questions { get; set; }

    [JsonProperty("complete")]
    public bool? Complete { get; set; }
}

public partial class Questions
{
    [JsonProperty("questionId")]
    public string QuestionId { get; set; }
}

public partial class QuestionId
{
    [JsonProperty("choices")]
    public string[] Choices { get; set; }
}

and my deserializing code is as below:

//JSon deserialization
JObject dragnsurveyRespondants = JObject.Parse(json);
// get JSON result objects into a list
searchResult = dragnsurveyRespondants.ToObject<Respondant>();
questions = dragnsurveyRespondants["questions"].Children().ToList();

Executing this code gives me a questions lists, but the questionId object, which is supposed to be composed of of a tab/list of question ID and answers, is null.

Ant idea?

Thank you!

Answer 1

Questions field must be dictionary. Because question key is dynamic. Also choices field must be object, because choice can an interger value or string value in the json file.

That's way, the classes are such as;

public class Respondant
    {
        [JsonProperty("id")]
        public string Id { get; set; }

        [JsonProperty("ip_address")]
        public string IpAddress { get; set; }

        [JsonProperty("created_at")]
        public DateTimeOffset CreatedAt { get; set; }

        [JsonProperty("questions")]
        public Dictionary<string, Question> Questions { get; set; }

        [JsonProperty("complete")]
        public bool? Complete { get; set; }
    }

    public partial class Question
    {
        [JsonProperty("timeStamp")]
        public DateTime timeStamp { get; set; }

        [JsonProperty("choices")]
        public List<object> choices { get; set; }
    }

using Newtonsoft.Json library, you can deserialize object such as;

var respondant = JsonConvert.DeserializeObject<Respondant>(jsonString);

To access question list;

var questionList =respondant.Questions

You can query by key in the list.

Answer 2

Sorry But your request json and class structure is not correct. here is what I could have created

public class Respondant
{
    [JsonProperty("id")]
    public string Id { get; set; }

    [JsonProperty("ip_address")]
    public string IpAddress { get; set; }

    [JsonProperty("created_at")]
    public DateTimeOffset CreatedAt { get; set; }

    [JsonProperty("questions")]
    public Questions[] Questions { get; set; }

    [JsonProperty("complete")]
    public bool? Complete { get; set; }
}

public partial class Questions
{
    [JsonProperty("questionId")]
    public string QuestionId { get; set; }

    public Question Question { get; set; }
}

public partial class Question
{
    [JsonProperty("choices")]
    public string[] Choices { get; set; }
}

code to create the json and serialize and Deserialize the object

        var question = new Question();

        question.Choices = new string[] { "A", "B", "C" };

        var questions = new List<Questions>();
        questions.Add(new Questions() { QuestionId = "5e6106600066d227a231ceb8", Question = question });

     

        var request = new Respondant()
        {
            Id = "5e6106600066d227a231ceb8",
            Questions = questions.ToArray()
        };
        var jsonObj = Newtonsoft.Json.JsonConvert.SerializeObject(request);


        var response = Newtonsoft.Json.JsonConvert.DeserializeObject<Respondant> (jsonObj);