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.