how to get json from controller code example

Example: how to return json data from mvc controller to view

When you do return Json(...) you are specifically telling MVC not to use a view, and to serve serialized JSON data. Your browser opens a download dialog because it doesn't know what to do with this data.

If you instead want to return a view, just do return View(...) like you normally would:

var dictionary = listLocation.ToDictionary(x => x.label, x => x.value);
return View(new { Values = listLocation });
Then in your view, simply encode your data as JSON and assign it to a JavaScript variable:

<script>
    var values = @Html.Raw(Json.Encode(Model.Values));
</script>