ASP.Net WEB API Failing POST Large JSON data from Mobile

Question

I am using ASP.net WEB api from Mobile.Its failing every time.I am getting this error.

Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.

I already added maxJsonLength on Webconfig

    <system.webServer>
    <modules>
      <remove name="FormsAuthentication" />
      <remove name="ApplicationInsightsWebTracking" />
      <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
    </modules>
    <validation validateIntegratedModeConfiguration="false" />
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="2147483648" />
      </requestFiltering>
    </security>
  </system.webServer>
  <system.web.extensions>
    <scripting>
      <webServices>
        <jsonSerialization maxJsonLength="2147483644"/>
      </webServices>
    </scripting>
  </system.web.extensions>

This is My controller how can i get then JSON inside postDataForSync Method ? for now its crashing after constructor method.

 public class MobileAPIController : Controller
{
    JavaScriptSerializer serializer;
    public MobileAPIController() {

        serializer = new JavaScriptSerializer();
        serializer.MaxJsonLength = Int32.MaxValue;

    }


    //
    //GET : MobileAPI/login

    public object login(string userId, string password)
    { 
    }

    //
    //GET : MobileAPI/getDataForSync
    public object getDataForSync(string userId) {

    }

    //
    //POST : MobileAPI/postDataForSync
    [HttpPost]
    public object postDataForSync(string syncData_)
    {
    }
}

Error ,

[ArgumentException: Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.
Parameter name: input]
   System.Web.Script.Serialization.JavaScriptSerializer.Deserialize(JavaScriptSerializer serializer, String input, Type type, Int32 depthLimit) +168
   System.Web.Mvc.JsonValueProviderFactory.GetDeserializedObject(ControllerContext controllerContext) +211
   System.Web.Mvc.JsonValueProviderFactory.GetValueProvider(ControllerContext controllerContext) +16
   System.Web.Mvc.ValueProviderFactoryCollection.GetValueProvider(ControllerContext controllerContext) +69
   System.Web.Mvc.ControllerBase.get_ValueProvider() +30
   System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +62
   System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +105
   System.Web.Mvc.Async.&lt;&gt;c__DisplayClass21.&lt;BeginInvokeAction&gt;b__19(AsyncCallback asyncCallback, Object asyncState) +743
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +14
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +343
   System.Web.Mvc.Controller.&lt;BeginExecuteCore&gt;b__1c(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState) +25
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +465
   System.Web.Mvc.Controller.&lt;BeginExecute&gt;b__14(AsyncCallback asyncCallback, Object callbackState, Controller controller) +18
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +20
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +374
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +16
   System.Web.Mvc.MvcHandler.&lt;BeginProcessRequest&gt;b__4(AsyncCallback asyncCallback, Object asyncState, ProcessRequestState innerState) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +384
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +48
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously) +159
</pre>
                        </code>
                    </td>
                </tr>
            </table>
            <br>
            <hr width=100% size=1 color=silver>
            <b>Version Information:</b>&nbsp;Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.3062.0

Thank you.

score 2 · Accepted Answer · edited Oct 03 '20 at 13:20

I used my method like this

prev method

[HttpPost]
public object postDataForSync(string syncData_)
{
}

Updated method

[HttpPost]
public object postDataForSync()
{
 Stream req = Request.InputStream;
 req.Seek(0, System.IO.SeekOrigin.Begin);
 string json = new StreamReader(req).ReadToEnd();
 MyModel model = JsonConvert.DeserializeObject<MyModel>(json);
}

This SO Answer helped me to fix this. - SO

score 1 · Answer 2 · answered Jul 24 '19 at 03:40

1

have you try add the MaxJsonDeserializerMembers under appsetting on your web config? like this, at least it works for me

  <appSettings>
    <add key="aspnet:MaxJsonDeserializerMembers" value="1500000" />
  </appSettings>

answered Jul 24 '19 at 03:40

Kira Hao

1,077
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ASP.Net WEB API Failing POST Large JSON data from Mobile

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