Jquery 如何获取DropDownList的值并将其传递到MVC5中的AJAX调用中？

我有一个MVC5应用程序，我有一个模型，定义如下：

public class Request
{
    ...

    [ForeignKey("State")]
    public int StateID { get; set; }

    public virtual State State { get; set; }

    public string ServiceName { get; set; }
}

        <div class="form-group">
            @Html.LabelFor(model => model.StateID, "State", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("StateID", null, "Please select a state", htmlAttributes: new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.StateID, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.ServiceName, "Service", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.ServiceName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.ServiceName, "", new { @class = "text-danger" })
            </div>
        </div>

我的状态模型定义如下：

public class State
{
    public int StateID { get; set; }
    public string StateCode { get; set; }
    public string StateName { get; set; }
}

    public JsonResult GetBusinessDesriptions(int state, string term)
    {
        var results = db.Users.OfType<Business>().Where(b => b.StateID == state && (term == null || b.Description.ToLower().Contains(term.ToLower()))).Select(x => new { id = x.StateID, value = x.Description }).Take(5).ToList();

        return Json(results, JsonRequestBehavior.AllowGet);
    }

在我看来，我正在工作，我有这样的想法：

public class Request
{
    ...

    [ForeignKey("State")]
    public int StateID { get; set; }

    public virtual State State { get; set; }

    public string ServiceName { get; set; }
}

        <div class="form-group">
            @Html.LabelFor(model => model.StateID, "State", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("StateID", null, "Please select a state", htmlAttributes: new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.StateID, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.ServiceName, "Service", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.ServiceName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.ServiceName, "", new { @class = "text-danger" })
            </div>
        </div>

---

因此，一旦用户在我的视图中选择了StateID，我如何将其值发送到AJAX调用和GetBusinessDescription方法，以便仅过滤处于所选状态的业务？

例如，在源选项中使用AJAX并传递额外的参数。这里StateId是state dropdownlist的id

$("#Service-Name").autocomplete({
    source: function( request, response ) {
        $.ajax({
          url: "/Home/GetBusinessDesriptions",
          dataType: "jsonp",
          data: {
            state:$("#StateID").val(),
            term: request.term
          },
          success: function( data ) {
            response( data );
          }
        });
      },
    minLength: 2,
    select: function (event, ui) {
        $("#Service-Name").val(ui.item.value);
        $("#Service-Name").text(ui.item.value);
    }
});

---

看一看，这很好，唯一需要做的就是将数据类型从jsonp更改为json。感谢您的回答。很高兴看到使用Jquery UI自动完成传递除所需“术语”之外的更多参数的实现。：）