MVC实现下拉框联动效果（单选）

@using (Html.BeginForm("aaai003sch", "aaa", FormMethod.Post, new { @class = "form-horizontal", role = "form" })){ @Html.AntiForgeryToken() <div class="modal-body">  <div class="form-horizontal">    <div class="form-group">     @Html.LabelFor(m => m.dept, new { @class = "col-sm-2 control-label" })      <div class="col-sm-10">       @Html.DropDownListFor(model => model.dept, Model.deptlist, new { @class = "form-control select2 ", style = "width: 100%;" })       @Html.ValidationMessageFor(m => m.dept, "", new { @class = "text-danger" })      </div>    </div>    <div class="form-group">    @ Html.LabelFor(m => m.job, new { @class = "col-sm-2 control-label" })      <div class="col-sm-10">       @Html.DropDownListFor(model => model.job, Model.joblist, new { @class = "form-control select2 page-select2-area", style = "width: 100%;" })       @Html.ValidationMessageFor(m => m.job, "", new { @class = "text-danger" })      </div>    </div>  </div> </div></div>

//根据城市获取酒店 $("#dept").change(function () {  var url = rootUrl + "aaa/GetJobByDept";   var dept = $(this).val(); //获取部门的值   var job = $("#job");   job.empty();  //清空当前职位的值   //这句很重要，因我们用的是select2插件，若没有用这个插件可以去掉这句   job.select2('val', '');   $.ajax({    cache: false,    type: "GET",    url: url,    data: { "Dept": dept},    success: function (data) {     $.each(data, function (id, option) {      job.append($('<option></option>').val(option.Id).html(option.Name));     });     job.trigger('change');    },    error: function (xhr, ajaxOptions, thrownError) {     toastr["error"]("请选择部门");    }   }); });

  [Description("根据部门获取职位")]  [AcceptVerbs(HttpVerbs.Get)]  [LoginAllowView]  public ActionResult GetJobByDept(string dept)  {   if (String.IsNullOrEmpty(dept))   {    throw new ArgumentNullException("dept");   }   StringBuilder sb = new StringBuilder();   sb = new StringBuilder();   sb.Append(" SELECT jobid,jobname ");   sb.Append(" FROM job_file ");   sb.Append(" LEFT JOIN dept_file ON jobdept = deptid ");   sb.AppendFormat(" WHERE deptid='{0}'", dept);   DataTable dt = sqlHelper.getData(sb.ToString());   var result = dt.AsEnumerable().Select(row => new Item   {    Name = Utils.ObjToStr(row["jobname"]),    Id = Utils.ObjToInt(row["jobid"], 0)   }).ToList();   return Json(result, JsonRequestBehavior.AllowGet);  }