json结果，在视图mvc中结果为“ undefined”

Question

when I pass the following linq result to my dropdown list ,I get "undefined" there,here I have result(in controller),I know the reason could be after "select new" I didn't specified any specific class but I need it to be like this,

    var newlist_of_device_types = (from z in DB.t_device_details
                                           where z.type_id == DB.t_device_type.Where(t => t.device_type == "PLC")
                                          .Select(t => t.type_id)
                                          .FirstOrDefault()
                                           select new
                                           {

                                           model = (z.model + "-" + z.producer),
                                          }).Where(z => z.model != null).ToList();

" View "

  $.ajax({
                        dataType: "json",
                        type: "POST",
                        url: "@Url.Action("deviceTypeList","AdminTool")",
                        contentType: "application/json; charset=utf-8",
                        data: JSON.stringify({ "flg": flg_dvType, }),
                        success: function (data) {
                            mydata_deviceType = data;
                        }

                    });

The screen shot of what I get in Ajax

Answer 1

you need to return json from controller. I see you are using POST (make sure if u use get then you need to allow get - JsonRequestBehavior) So do like this:

    var newlist_of_device_types = (from z in DB.t_device_details
                                       where z.type_id == DB.t_device_type.Where(t => t.device_type == "PLC")
                                      .Select(t => t.type_id)
                                      .FirstOrDefault()
                                       select new
                                       {

                                       model = (z.model + "-" + z.producer),
                                      }).Where(z => z.model != null).ToList();
    return Json(newlist_of_device_types);

And your ajax is actually correct:

    $.ajax({
        url: "@Url.Action("deviceTypeList","AdminTool")",
        type: "POST",
        data: JSON.stringify(jsonObject),
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        error: function (response) {
            alert(response.responseText);
    },
        success: function (response) {
            var $select = $('#ID of your dropdown list');
      $.each(response, function(i, m) {
     console.log(m);
     var option = $('<option>', {
     value: m.model //since you have no id here
   }).html(m.model).appendTo($select);
        console.log(option);
      });

        }
    });

Hope this helps!!

Maybe you can post a screenshot of your debugging console in browser so i can see the data