JsonConvert.DeserializeObject error mvc asp.net newtonjson

Question

I use HttpRequestMessage my model is some different VirtualStock. My API JSON model as below

[{
        "_id": "5f2d66ae6abb1d6870e926ac",
        "MessageId": "EAD8B97887FFC1F180F3005056BF2302",
        "MessageType": "CreateDiscount",
        "RequestedBy": "AAA",
        "RequestedDate": "2020-08-07T17:22:58.000Z",
        "Data": {
            "_id": "5f2d66ae6abb1d6870e926ad",
            "Sku": "A",
            "SkuId": "EAD8B97887FFC0F180F3005056BF2302",
            "Price": 1759.17,
            "PurchasePrice": 1768.88,
            "StartDateTime": "2020-08-07T17:24:34.000Z",
            "EndDateTime": "2020-09-01T00:00:00.000Z",
            "VirtualStock": "1000",
            "MaximumQuantityForCart": 10,
            "CurrencyCode": "949"
        },
        "__v": 0
    },
    {
        "_id": "5f2d65daf7168b686d9474b9",
        "MessageId": "EAD8B8F92D90CDF180F3005056BF2302",
        "MessageType": "UpdateDiscount",
        "RequestedBy": "AAA",
        "RequestedDate": "2020-08-07T17:19:26.000Z",
        "Data": {
            "_id": "5f2d65daf7168b686d9474c5",
            "Sku": "A",
            "SkuId": "EAD8B8F92D90C5F180F3005056BF2302",
            "DiscountId": "8c3975a0-ea85-48e9-9c31-ea488bdad5c4",
            "Price": 296.2,
            "PurchasePrice": 239.91,
            "StartDateTime": "2020-08-01T14:35:00.000Z",
            "EndDateTime": "2020-08-07T17:23:08.000Z",
            "VirtualStock": {
                "Value": "100",
                "IsAssigned": true
            },
            "MaximumQuantityForCart": 25,
            "CurrencyCode": "949"
        },
        "__v": 0
    }
]

I defined my model VirtualStock like object and nullable.

public object? VirtualStock { get; set; }

but I get error parsing how can fix this?

I saw with debug Deserialize Success but showing JSON GetDiscount method I have exceptions

controller code as below

public IActionResult Discount()
{
    return View();
}
public async Task<IActionResult> GetDiscount()
{
    return Json(new { data = await _log.GetAllAsync("http://192.168.57.175/DiscountLog?pagesize=9&page=16") });
}

my Repository

public async Task<IEnumerable<T>> GetAllAsync(string url)
{
    var request = new HttpRequestMessage(HttpMethod.Get, url);

    var client = _clientFactory.CreateClient();

    HttpResponseMessage response = await client.SendAsync(request);
    if (response.StatusCode == System.Net.HttpStatusCode.OK)
    {
        var jsonString = await response.Content.ReadAsStringAsync();

        var jsonSerializerSettings = new JsonSerializerSettings()
        {
            NullValueHandling = NullValueHandling.Ignore,
            MissingMemberHandling = MissingMemberHandling.Ignore
        };

        return JsonConvert.DeserializeObject<IEnumerable<T>>(jsonString,jsonSerializerSettings);
    }

    return null;
}

My error:

An unhandled exception occurred while processing the request. NotSupportedException: The collection type 'System.Object' on 'RetailLogWeb.Models.LogItem.VirtualStock' is not supported. System.Text.Json.JsonPropertyInfoNotNullable<TClass, TDeclaredProperty, TRuntimeProperty, TConverter>.GetDictionaryKeyAndValueFromGenericDictionary(ref WriteStackFrame writeStackFrame, out string key, out object value)

NotSupportedException: The collection type 'System.Object' on 'RetailLogWeb.Models.LogItem.VirtualStock' is not supported. System.Text.Json.JsonPropertyInfoNotNullable<TClass, TDeclaredProperty, TRuntimeProperty, TConverter>.GetDictionaryKeyAndValueFromGenericDictionary(ref WriteStackFrame writeStackFrame, out string key, out object value) System.Text.Json.JsonPropertyInfo.GetDictionaryKeyAndValue(ref WriteStackFrame writeStackFrame, out string key, out object value) System.Text.Json.JsonSerializer.HandleDictionary(JsonClassInfo elementClassInfo, JsonSerializerOptions options, Utf8JsonWriter writer, ref WriteStack state) System.Text.Json.JsonSerializer.Write(Utf8JsonWriter writer, int originalWriterDepth, int flushThreshold, JsonSerializerOptions options, ref WriteStack state) System.Text.Json.JsonSerializer.WriteAsyncCore(Stream utf8Json, object value, Type inputType, JsonSerializerOptions options, CancellationToken cancellationToken) Microsoft.AspNetCore.Mvc.Infrastructure.SystemTextJsonResultExecutor.ExecuteAsync(ActionContext context, JsonResult result) Microsoft.AspNetCore.Mvc.Infrastructure.SystemTextJsonResultExecutor.ExecuteAsync(ActionContext context, JsonResult result) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|29_0<TFilter, TFilterAsync>(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext<TFilter, TFilterAsync>(ref State next, ref Scope scope, ref object state, ref bool isCompleted) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters() Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted) Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope) Microsoft.AspNetCore.Routing.EndpointMiddleware.g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger) Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context) Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

Try researching the error. You can't serialize into object. — CodeCaster
This is ASP.NET Core, correct? You may want to add that to the question tags to get the right folks looking at the question. Also, does this post help at all? — Tawab Wakil
I added services.AddControllers().AddNewtonsoftJson(); it's works! thnks man :) @TawabWakil — Mustafa Hamit

Tawab Wakil Tawab Wakil · Accepted Answer · 2020-08-10T16:49:18

OP figured it out as shared in the comments, but I'll provide an answer here just to close out the question. As explained in this answer, the solution was to add a variant of this line:

services.AddControllers().AddNewtonsoftJson();

This was needed because Newtonsoft.Json was removed during a recent upgrade to .NET Core, and this adds it back in. Note that this assumes you have the Microsoft.AspNetCore.Mvc.NewtonsoftJson package installed.

More info here.

JsonConvert.DeserializeObject error mvc asp.net newtonjson

1 Answers