Jquery 更改功能似乎工作，但没有做任何事情

Question

我有 2 个带有 jquery 代码的单选按钮，它们仅使用他们选择的选项重建一个下拉列表。我有下面的代码，它转到正确的方法，构建选择列表的方法正常工作，在方法完成后，下拉列表项根本不会改变。一切似乎都是正确的，但它只是不起作用。有人有什么想法吗？

查看

$('#singleSpacingRadio').change(function () {
        var url = "/Home/NumberOfPagesList?id=" + $('#singleSpacingRadio').val();

        $.getJSON(url, function (data) {
            var items = "<option>--Test--</option>";
            $.each(data, function (i, numberOfPages) {
                items += "<option value='" + numberOfPages.Value + "'>" + numberOfPages.Text + "</option>";
            });
            $("#numberOfPagesList").html(items);
        });
    });

    $('#doubleSpacingRadio').change(function () {
        var url = "/Home/NumberOfPagesList?id=" + $('#doubleSpacingRadio').val();

        $.getJSON(url, function (data) {
            var items = "<option>--Test--</option>";
            $.each(data, function (i, numberOfPages) {
                items += "<option value='" + numberOfPages.Value + "'>" + numberOfPages.Text + "</option>";
            });
            $("#numberOfPagesList").html(items);
        });
    });

<div class="row">
    @Html.LabelFor(model => model.Spacing, "Spacing:")
    @Html.RadioButtonFor(model => model.Spacing, "Single", new { id = "singleSpacingRadio" }) Single
    @Html.RadioButtonFor(model => model.Spacing, "Double", new { id = "doubleSpacingRadio" }) Double
</div>

控制器

public ActionResult NumberOfPagesList(string id)
    {
        var numberOfPagesList = from n in NumberOfPages.GetNumberOfPages()
                          where n.Spacing == id
                          select n;

        if (HttpContext.Request.IsAjaxRequest())
        {
            return Json(new SelectList(numberOfPagesList.ToArray(), "numberOfPagesValue", "numberOfPagesName"), JsonRequestBehavior.AllowGet);
        }
        else
        {
            return RedirectToAction("Contact");
        }
    }

public class NumberOfPages
{
    public string Name { get; set; }
    public string Value { get; set; }
    public string Spacing { get; set; }

    public static IQueryable<NumberOfPages> GetNumberOfPages()
    {
        return new List<NumberOfPages>
        {
            new NumberOfPages
            {
                Name = "1 Page (Approx. 550 Words)",
                Value = "1",
                Spacing = "Single"
            },
            new NumberOfPages
            {
                Name = "1 Page (Approx. 275 Words)",
                Value = "1",
                Spacing = "Double"
            },
            new NumberOfPages
            {
                Name = "50 Pages (Approx. 13750 Words)",
                Value = "50",
                Spacing = "Double"
            }
        }.AsQueryable();
    }

Answer 1

把html改成

@Html.RadioButtonFor(m => m.Spacing, "Single", new { @class = "spacing", id="single" })
<label for="single">Single</label>
@Html.RadioButtonFor(m => m.Spacing, "Double", new { @class = "spacing", id="double" })
<label for="double">Double</label>

和脚本

$('.spacing').click(function() {
  var select = $("#numberOfPagesList");
  select.empty().append($('<option></option>').val('').text('--Test--'));
  var url = '@Url.Action("NumberOfPagesList", "Home")';
  $.getJSON(url, { id: $(this).val() }, function (data) {
    $.each(data, function (i, item) {
      select.append($('<option></option>').val(item.Value).text(item.Name));
    });
  });
});

另外请注意，您不需要将您的收藏返回到 SelectList，并且只需要以下内容

return Json(numberOfPagesList, JsonRequestBehavior.AllowGet);