MVC JsonResult camelCase serialization [duplicate]

Answer 1

If you want to return a json string from your action which adheres to camelcase notation what you have to do is to create a JsonSerializerSettings instance and pass it as the second parameter of JsonConvert.SerializeObject(a,b) method.

public string GetSerializedCourseVms()
    {
        var courses = new[]
        {
            new CourseVm{Number = "CREA101", Name = "Care of Magical Creatures", Instructor ="Rubeus Hagrid"},
            new CourseVm{Number = "DARK502", Name = "Defence against dark arts", Instructor ="Severus Snape"},
            new CourseVm{Number = "TRAN201", Name = "Transfiguration", Instructor ="Minerva McGonal"}
        };
        var camelCaseFormatter = new JsonSerializerSettings();
        camelCaseFormatter.ContractResolver = new CamelCasePropertyNamesContractResolver();
        return JsonConvert.SerializeObject(courses, camelCaseFormatter);
    }

Answer 2

The Json functions of the Controller are just wrappers for creating JsonResults:

protected internal JsonResult Json(object data)
{
    return Json(data, null /* contentType */, null /* contentEncoding */, JsonRequestBehavior.DenyGet);
}

protected internal JsonResult Json(object data, string contentType)
{
    return Json(data, contentType, null /* contentEncoding */, JsonRequestBehavior.DenyGet);
}

protected internal virtual JsonResult Json(object data, string contentType, Encoding contentEncoding)
{
    return Json(data, contentType, contentEncoding, JsonRequestBehavior.DenyGet);
}

protected internal JsonResult Json(object data, JsonRequestBehavior behavior)
{
    return Json(data, null /* contentType */, null /* contentEncoding */, behavior);
}

protected internal JsonResult Json(object data, string contentType, JsonRequestBehavior behavior)
{
    return Json(data, contentType, null /* contentEncoding */, behavior);
}

protected internal virtual JsonResult Json(object data, string contentType, Encoding contentEncoding, JsonRequestBehavior behavior)
{
    return new JsonResult
    {
        Data = data,
        ContentType = contentType,
        ContentEncoding = contentEncoding,
        JsonRequestBehavior = behavior
    };
}

JsonResult internally uses JavaScriptSerializer, so you don't have control about the serialisation process:

public class JsonResult : ActionResult
{
    public JsonResult()
    {
        JsonRequestBehavior = JsonRequestBehavior.DenyGet;
    }

    public Encoding ContentEncoding { get; set; }

    public string ContentType { get; set; }

    public object Data { get; set; }

    public JsonRequestBehavior JsonRequestBehavior { get; set; }

    /// <summary>
    /// When set MaxJsonLength passed to the JavaScriptSerializer.
    /// </summary>
    public int? MaxJsonLength { get; set; }

    /// <summary>
    /// When set RecursionLimit passed to the JavaScriptSerializer.
    /// </summary>
    public int? RecursionLimit { get; set; }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }
        if (JsonRequestBehavior == JsonRequestBehavior.DenyGet &&
            String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
        {
            throw new InvalidOperationException(MvcResources.JsonRequest_GetNotAllowed);
        }

        HttpResponseBase response = context.HttpContext.Response;

        if (!String.IsNullOrEmpty(ContentType))
        {
            response.ContentType = ContentType;
        }
        else
        {
            response.ContentType = "application/json";
        }
        if (ContentEncoding != null)
        {
            response.ContentEncoding = ContentEncoding;
        }
        if (Data != null)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            if (MaxJsonLength.HasValue)
            {
                serializer.MaxJsonLength = MaxJsonLength.Value;
            }
            if (RecursionLimit.HasValue)
            {
                serializer.RecursionLimit = RecursionLimit.Value;
            }
            response.Write(serializer.Serialize(Data));
        }
    }
}

You have to create your own JsonResult and write your own Json Controller functions (if you need / want that). You can create new ones or overwrite existing ones, it is up to you. This link might also interest you.