Invalid JSON primitive: object

Question

I am trying to send a stringified JSON object to MVC method via the following jQuery Ajax call:

$.ajax({
           type: "POST",
           url: "UpdateItem",
           contentType: "application/json; charset=utf-8",
           dataType: "json",
           processData : false,
           data:
               {
                    item: JSON.stringify(_item)
               },
           success: function (data) {
               alert(data);
           },
           error: function (x, t, m, b) {
               DisplayErrorMessage(x.responseText);
           }
       });

and the stringified version of my data is as follows:

{
    "Id": 4,
    "ParentId": 1,
    "TypeId": 2,
    "TypeText": "Solid",
    "ItemNo": 8,
    "StandartTypeId": 7,
    "StandartTypeText": "Dept",
    "GradeTypeId": 6,
    "GradeTypeText": null,
    "Thickness": 0.044,
    "ThicknessToleranceId": 1,
    "ThicknessToleranceText": null,
    "Width": 42,
    "MinWeightId": 6,
    "MinWeight": null,
    "MinWeight2": null,
    "MaxWeightId": 8,
    "MaxWeight1": null,
    "MaxWeight2": null,
    "DefId": null,
    "Quantity": 330690,
    "QuantityToleranceId": 3,
    "QuantityToleranceText": "",
    "ProductionDate": "2014-11-05T22:00:00.000Z",
    "PortId": 3,
    "PortText": null,
    "DeliveryDate": "2014-10-08T21:00:00.000Z",
    "MaterialTypeId": 2,
    "MaterialTypeText": "",
    "FeePrepaid": 30,
    "Price": 525,
    "Extra1": 0,
    "Extra1": 0,
    "CurrencyId": 2,
    "CurrencyText": "",
    "StatusId": 2,
    "StatusText": "",
    "ReasonId": null,
    "ReasonText": null,
    "Note": "New note",
    "CreateDate": "2014-11-06T09:12:29.661Z",
    "CreateUserId": 0,
    "CreateUserText": "",
    "CancelDate": null,
    "CancelUserId": null,
    "CancelUserText": null,
    "ChemicalProperties": null,
    "TechnicalProperties": null,
    "Remarks": null
}

I have successfully validated my JSON object via http://jsonlint.com/.

I try to get the response into the following method :

public JsonResult UpdateItem(string json)
{
    var js = new JavaScriptSerializer();
    var deserializedItem = (object[])js.DeserializeObject(json);


    return Json(null);
}

But when I try to post via Ajax I get the following error Message before ASP.NET MVC Controller method call:

Invalid JSON primitive: object. Exception Details: System.ArgumentException: Invalid JSON primitive: object.

And my Stack Trace is as follows:

[ArgumentException: Invalid JSON primitive: object.]
System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializePrimitiveObject() +915
System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal(Int32 depth) +597
System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeList(Int32 depth) +354
System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal(Int32 depth) +531
System.Web.Script.Serialization.JavaScriptObjectDeserializer.BasicDeserialize(String input, Int32 depthLimit, JavaScriptSerializer serializer) +108
System.Web.Script.Serialization.JavaScriptSerializer.Deserialize(JavaScriptSerializer serializer, String input, Type type, Int32 depthLimit) +210
System.Web.Script.Serialization.JavaScriptSerializer.DeserializeObject(String input) +86
System.Web.Mvc.JsonValueProviderFactory.GetDeserializedObject(ControllerContext controllerContext) +191
System.Web.Mvc.JsonValueProviderFactory.GetValueProvider(ControllerContext controllerContext) +19
System.Web.Mvc.<>c__DisplayClassc.<GetValueProvider>b__7(ValueProviderFactory factory) +34
System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +145
System.Linq.WhereSelectEnumerableIterator`2.MoveNext() +171
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +460
System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
System.Web.Mvc.ValueProviderFactoryCollection.GetValueProvider(ControllerContext controllerContext) +281
System.Web.Mvc.ControllerBase.get_ValueProvider() +40
System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +60
System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +117
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__1e(AsyncCallback asyncCallback, Object asyncState) +446
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +302
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__17(AsyncCallback asyncCallback, Object asyncState) +30
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +382
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +317
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +15
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__2(AsyncCallback asyncCallback, Object asyncState) +71
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +130
System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +249
System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +50
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +301
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

Answer 1

Just run with my code In my reactjs

$.ajax({
            type: 'POST',
            url: 'http://example.com/ExampleService/ExampleMethod',
            //data: JSON.stringify({transferData: objImages}), => Wrong
            //data: { transferData: JSON.stringify(objImages) }, => Wrong
            //data: JSON.stringify(objImages), => Wrong
            data: JSON.stringify({ 'transferData': JSON.stringify(objImages) }), // transferData is name
            contentType: 'application/json; charset=utf-8',
            dataType: 'json',
            success: function (data) {
                alert(data);
            },
            failure: function (errMsg) {
                alert(errMsg);
            }
        });

In asp.net mvc webservice

public ActionResult ExampleMethod(string transferData)
    {
        //dynamic transferObj = JsonConvert.DeserializeObject(transferData);
        //return Json(transferObj);

        return Json(transferData);
    }

Answer 2

Setting the "traditional" property of the Ajax request to true would suffice.

And also as Michael suggests, instead of multiple values, only single parameter should be set as follows:

The final Ajax call should be:

$.ajax({
       type: "POST",
       url: "UpdateItem",
       contentType: "application/json; charset=utf-8",
       dataType: "json",
       traditional: true,
       processData : false,
       data: JSON.stringify(_item),
       success: function (data) {
           alert(data);
       },
       error: function (x, t, m, b) {
           DisplayErrorMessage(x.responseText);
       }
   });

Answer 3

Did you try with :

data: JSON.stringify(_item)

Just a guess but I think using:

data:
           {
                item: JSON.stringify(_item)
           }

won't get you what you want.

Since you're waiting for a String in the controller, a String should be passed in the request.

If you want multiple objects you'll have to make a variable that will convert to something like :

JSON.stringify(_items) => "[{id:1},{id:2}]";

And then use it in : data: JSON.stringify(_item)