Viewbag not updating

目前，我有一些内联javascript，它使一个ajax调用部分视图控制器，它应该已经更新了viewbag随着它。然而，情况似乎并非如此，数据似乎从主视图中持续存在，这是null，因为它从未在那里设置，如果它被设置，那么数据仍然会持续存在(测试)。

这是我的javascript ajax调用。

  $.ajax({
            url: btn.data('action-url'),
            data: {
                id: btn.data('id')
            },
            type: 'GET',
            success: function (data) {
                //delete all panels before showing new ones
                $('.panel.panel-default').remove();
                //push the new panels into the view
                //$('#dash-content').html(data);
                //Construct the partial view to be input into the main view
                //Checks to see if browser supports templates
                if ('content' in document.createElement('template')) {
                    var widgetModel = @Html.Raw(Json.Encode(ViewBag.widgets));
                    for (var i = 0; i < widgetModel.length; i++) {
                        var clone = loadwidgets(widgetModel[i]); //This function is in an external js file
                        var inputDestination = document.querySelector('#col2');
                        inputDestination.appendChild(clone);
                        console.log(inputDestination);
                    }
                }

这里是它调用的Action

  public ActionResult Dashboard(int? id)
    {
        ModelState.Clear();
        //get all widgets associated dashboard
        var getWidgetsQuery = (from widgets in db.widgets
                               where widgets.DashID == id
                               select widgets);
        ViewBag.widgets = getWidgetsQuery.ToList();

        return PartialView();
    }

  public ActionResult DashboardJson(int? id)
    {
        //get all widgets associated dashboard
        var getWidgetsQuery = (from widgets in db.widgets
                               where widgets.DashID == id
                               select widgets);
        var widgets = getWidgetsQuery;
        return Json(widgets, JsonRequestBehavior.AllowGet);
    }

var widgetModel = @Html.Raw(Json.Encode(ViewBag.widgets));

widgetModel = data;