Deserialize nested JSON into C# childObject classes

Question

I want to get nested json object result after its deserialization as in following code.

var matrixDto = new QuestionMatrixDto();
           
// First child Dto:

matrixDto.displayAnswers = "displayAnswers Test";
matrixDto.questionWeight = 10;

// Second child dto:

var essayDto = new QuestionEssayDto();
essayDto.addToBank= true;
essayDto.questionLength = 10;

// Parent Dto:

var obj = new V2ObjectDto();
obj.name = "object test";
obj.childObjects.Add(matrixDto);
obj.childObjects.Add(essayDto);

JsonSerializerSettings settings = new JsonSerializerSettings
                {
                    TypeNameHandling = TypeNameHandling.All
                };

var serlizeObj = JsonConvert.SerializeObject(obj,settings );
 
var deserlizeObj = JsonConvert.DeserializeObject<V2ObjectDto>(serlizeObj,settings );

But now when I am trying to access

var matrixResult = deserlizeObj.childObjects.FirstOrDefault();
matrixResult.displayAnswers;

matrixResult.displayAnswers is not accessible and have no definition

I need same result as before serialize object after its deserialization, but the problem is that I am not able to get any question (or child Dto) attribute value after its deserialization.

Serialization result:

{
    "id": null,
    "text": null,
    "guid": null,
    "containerId": null,
    "name": "object test",
    "testName": null,
    "childObjects": [{
            "questionText": null,
            "testStatus": null,
            "displayAnswers": "displayAnswers Test",
            "questionWeight": 10,
            "answers": [],
            "questions": [],
            "questionAnswersDto": [],
            "userAnswer": {
                "selectedAnswers": [],
                "id": null,
                "comments": null,
                "questionId": null
            },
            "keywords": null,
            "commentObj": {
                "watermarkText": null,
                "commentText": null,
                "textType": null,
                "userComment": null,
                "isCorrect": false,
                "totalCharacters": null
            },
            "questionSelectDto": {
                "questionType": null,
                "addToBank": false,
                "numberOfAnswersAllow": null,
                "displayAnsweras": null,
                "id": null,
                "text": null,
                "guid": null,
                "containerId": null,
                "name": "",
                "testName": null,
                "childObjects": [],
                "objectType": 0,
                "sortOrder": 0,
                "height": null,
                "keywords": null
            },
            "feedBackText": null,
            "questionType": null,
            "addToBank": false,
            "numberOfAnswersAllow": null,
            "displayAnsweras": null,
            "id": null,
            "text": null,
            "guid": null,
            "containerId": null,
            "name": "",
            "testName": null,
            "childObjects": [],
            "objectType": 0,
            "sortOrder": 0,
            "height": null
        }, {
            "id": null,
            "questionText": null,
            "testStatus": null,
            "questionWeight": 10,
            "minCharecters": null,
            "maxCharecters": null,
            "commentObj": {
                "watermarkText": null,
                "commentText": null,
                "textType": null,
                "userComment": null,
                "isCorrect": false,
                "totalCharacters": null
            },
            "keywords": null,
            "userAnswer": {
                "essayText": null,
                "id": null,
                "comments": null,
                "questionId": null
            },
            "feedBackText": null,
            "questionType": null,
            "addToBank": false,
            "numberOfAnswersAllow": null,
            "displayAnsweras": "displayAnswers for Test",
            "text": null,
            "guid": null,
            "containerId": null,
            "name": "",
            "testName": null,
            "childObjects": [],
            "objectType": 0,
            "sortOrder": 0,
            "height": null
        }
    ],
    "objectType": 0,
    "sortOrder": 0,
    "height": null,
    "keywords": null
}

Question Dto are the child dto of ObjectDto like

class QuestionDto : V2ObjectDto

Note the parent Class attribute will remain same but child class and its attributes will be changed with its question type as I mentioned in above code.

Please help me to sort out this issue or let me know about any other possible solution for it.

Is your question how to deserialize derived types with a common base type in the C# model? — ProgrammingLlama, Mar 05 '21 at 08:38
Does this answer your question? [Json.net serialize/deserialize derived types?](https://stackoverflow.com/questions/8513042/json-net-serialize-deserialize-derived-types) — Drag and Drop, Mar 05 '21 at 08:41
https://stackoverflow.com/questions/8241392/deserializing-heterogenous-json-array-into-covariant-list-using-json-net — Drag and Drop, Mar 05 '21 at 08:43
its seems like its worked but i am getting another issue now .JsonSerializerSettings settings = new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All }; var serlizeObj = JsonConvert.SerializeObject(obj, settings); var deserlizeObj = JsonConvert.DeserializeObject (serlizeObj, settings); var matrixResult= deserlizeObj.childObjects.FirstOrDefault(); \ matrixResult.displayAnswers;//this line are not accesibe — Naveed Shahid, Mar 05 '21 at 08:52
Why not follow a consistent pattern? When you follow a fixed pattern, Json's conversion and vice versa work well. — Meysam Asadi, Mar 05 '21 at 09:25
@meysamasadi can you please give me an example regarding this? — Naveed Shahid, Mar 05 '21 at 11:04

score 0 · Answer 1 · answered Mar 05 '21 at 13:05

In the following example, the classes are in a hierarchical structure. If it is serialized correctly, the reverse operation will be performed correctly.

public class BaseClass
{
    public int ID { get; set; }
    public ChildClass childObject { get; set; }
}
public class ChildClass
{
    public int ID { get; set; }
    public List<NodeClass> nodeObjects { get; set; }
}
public class NodeClass
{
    public string Name { get; set; }
    public int Order { get; set; }
}

now use

BaseClass bc = new BaseClass();
bc.ID = 1;
bc.childObject = new ChildClass()
{
   ID = 1,
   nodeObjects=new List<NodeClass>()
   {
       new NodeClass(){Name="Name 1",Order =1},
       new NodeClass(){Name="Name 2",Order =2},
       new NodeClass(){Name="Name 3",Order =3},
   }
};

string json = JsonConvert.SerializeObject(bc);
BaseClass result = JsonConvert.DeserializeObject<BaseClass>(json);

Deserialize nested JSON into C# childObject classes

1 Answers1