你有一个CascadingDropDown使用ASP.NET MVC吗？

@Html.DropDownList("PrimaryList", ViewBag.PrimaryList as SelectList, "Select One", new { id = "PrimaryList" })
@Html.DropDownList("SecondaryList", Enumerable.Empty<SelectListItem>(), "Select One", new { id = "SecondaryList" })

public ActionResult GetSecondaryList(string id)
{
    // 根据主要选项的ID获取次要选项的数据
    var secondaryList = GetSecondaryListData(id);
    return Json(new SelectList(secondaryList, "Value", "Text"), JsonRequestBehavior.AllowGet);
}

$("#PrimaryList").change(function () {
    var id = $(this).val();
    $.getJSON("/ControllerName/GetSecondaryList", { id: id }, function (data) {
        var items =<option>Select One</option>";
        $.each(data, function (i, item) {
            items +=<option value='" + item.value + "'>" + item.text + "</option>";
        });
        $("#SecondaryList").html(items);
    });
});