I was working on an ASP.NET Core API where I have an endpoint that accepts a `CarModel`. This `CarModel` has a property named `CarDetails` which is declared as dynamic because it's used by multiple endpoints. Therefore, I am trying to maintain the same structure while attempting to resolve the issue of ValueKind = Object.

[ApiController]
    [Route("api/[controller]")]
    public class CarController : ControllerBase
    {
        [HttpPost]
        public IActionResult Post([FromBody] CarModel model)
        {
            try
            {
                // Accessing dynamic properties
                JsonElement jsonStr = model.CarDetails;
                var dynamicObject = JsonSerializer.Deserialize<JsonElement>(jsonStr);

                // Use the dynamic properties as needed
                
                return Ok("Successfully processed the request.");
            }
            catch (Exception ex)
            {
                return StatusCode(500, "An error occurred: " + ex.Message);
            }
        }
    }

    public class CarModel
    {
        public int Identifier { get; set; }
        public string VehicleBrand { get; set; }
        public dynamic CarDetails { get; set; }
    }
The action method accepts an instance of the CarModel class as input. The CarModel class has properties Identifier, VehicleBrand, and a dynamic property CarDetails. Inside the action method, you can access the dynamic properties of CarDetails as needed. 
CarDetails property from the model object, which is assumed to be of type JsonElement, then deserializes the jsonStr variable into a dynamic object dynamicObject using the JsonSerializer.Deserialize method from the System.Text.Json namespace.

 Here's the JSON payload: 
{
  "Identifier": 233,
  "VehicleBrand": "Kia",
  "CarDetails": {
    "CustomerLastName": "Johnson",
    "CustomerTitle": "Mr",
    "PlanType": "Help Extension",
    "ServiceAdvisor": "Jeff Matle",
    "DealerName": "Goldwagen Pretoria"
  }
}
but when i'm using above code Results of dynamicObject : 
ValueKind = Object :" {
    "CustomerLastName": "Johnson",
    "CustomerTitle": "Mr",
    "PlanType": "Help Extension",
    "ServiceAdvisor": "Jeff Matle",
    "DealerName": "Goldwagen Pretoria"
  }"
2

Based on our experience, it's possible that both libraries were mixed up during serialization and deserialization:

public async Task PostAsync([FromBody] CarModel model)
{
     var data = JsonConvert.DeserializeObject(model.ToString());
}

Mixing Newtonsoft.Json and System.Text.Json for serialization and deserialization can lead to compatibility issues and unexpected behavior. It's importent to maintain consistency in the usage of serialization libraries throughout the application to avoid such complications.

3

I'm joining a bit late to this discussion, but I've encountered a similar issue recently. A simple workaround that worked well for me is to send the JSON object as a string and then deserialize it back into the model within the controller. 

4

Based on our experience, we encountered a similar issue and found a solution:

We utilized System.Text.Json instead of Newtonsoft.Json and updated the code as follows:

using System.Text.Json;

string serializedCarObject = JsonSerializer.Serialize(model.CarDetails); // Instead of using JsonConvert.SerializeObject(model.CarDetails);

System.Text.Json can offer advantages such as improved performance and reduced dependencies. 

Using above we solution should result in proper serialization of the `model.CarDetails` object into a JSON string using System.Text.Json.

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