javascript - 级联下拉空不显示任何值

Question

我尝试创建级联下拉菜单，当我选择 kanwil 值时，我有 2 个下拉 kanwil 和分支出现分支值，但是当我在具有值“-1”的分支中选择默认值时，分支下拉列表为空，这是控制器中的操作索引

 public ActionResult Index(string PrmBranch="", string PrmWilayah = "")
        {
            
     
            string ParamWilayah = "";
            string Parambranch = "";
           

            if (PrmWilayah != "")
            {
                ParamWilayah = PrmWilayah.Trim();
                ViewBag.wilayahsearch = PrmWilayah.Trim();
                
            }
            else
            {
                ParamWilayah = "-1";
            }



            if ( PrmBranch !="")
            {
                Parambranch = PrmBranch.Trim();
                ViewBag.branchsearch = PrmBranch.Trim();
            }
            else
            {
                Parambranch = "-1";
               

            }

            //select from database
         
        }

           

风景

 @using (Html.BeginForm("Index", "CreateAccount", FormMethod.Post))
{
  Wilayah
  <div class="form-group">
  <div class="input-group date">
  <select class="form-control" id="WilayahDropdown" name="PrmWilayah" style="text-align: center"></select>
                                                      
 <span class="input-group-addon">                                                           <span class="glyphicon glyphicon-institution fa fa-institution"></span>
  </span>
  </div>
  </div>
  </div>
<div class="col-sm-4">
                                               
 Branch
<div class="form-group">
 <div class="input-group date">
<select class="form-control" id="BranchDropdown" name="PrmBranch" style="text-align: center"></select>
<span class="input-group-addon">
<span class="glyphicon glyphicon-institution fa fa-institution"></span>
</span>
 </div>
 </div>
</div>
 <div class="form-group">
<div class="input-group date">
<input type="submit" class="btn btn-primary" value="Search" name="" />
 </div>
</div>
</div>
 <input type="text" value="@ViewBag.wilayahsearch" id="btnWilayahsearch" />
<input type="text" value="@ViewBag.branchsearch" id="btnbranchsearch" />
}
    <script type="text/javascript">
        @Model.JavascriptToRun


        
        $(document).ready(function () {
            var Wilayahsearch = $('#btnWilayahsearch').val();
            var branchsearch = $('#btnbranchsearch').val();


            getWilayah();
            if (Wilayahsearch.length > 0) {
                if (Wilayahsearch == "-1")  {
                    
                    getBranch();
                }
                else if (branchsearch != "-1") {
                    getbranchselect(branchsearch);
                }

                else if (Wilayahsearch != "-1") {
                    getwilayahselect(Wilayahsearch);
                    getBranchWil();
                }
            }
            else if (branchsearch.length < 0) {
                getbranch();

            }
            else {
                getBranchWil();
            }
});
function getBranchWil() {
            $.ajax({
                type: "GET",
                url: '@Url.Content("~/CreateAccount/getBranchWil")',
                data: { kanwil: $('#btnWilayahsearch').val() },
                success: function (data) {
                    var s = '<option value="-1">--- Branch ---</option>';
                    for (var i = 0; i < data.length; i++) {
                        s += '<option value="' + data[i].Branch + '">' + data[i].Branch + ' - ' + data[i].Branch_Name + '</option>';
                    }
                    $("#BranchDropdown").html(s);
                }
            });
        }

        function getWilayah() {
            $.ajax({
                type: "GET",
                url: '@Url.Content("~/CreateAccount/getWilayah")',
                data: "{}",
                success: function (data) {
                    var s = '<option value="-1">--- Wilayah ---</option>';
                    for (var i = 0; i < data.length; i++) {
                        s += '<option value="' + data[i].Kanwil + '">' + data[i].Kanwil + ' - ' + data[i].Kanwil_Name + '</option>';
                    }
                    $("#WilayahDropdown").html(s);
                }
            });
        }
        function getwilayahselect(e) {
            $.ajax({
                type: "GET",
                url: '@Url.Content("~/CreateAccount/getWilayah")',
                data: "{}",
                success: function (data) {
                    var namaWilayah = "";
                    for (var i = 0; i < data.length; i++) {
                        if (data[i].Kanwil == e.trim()) {
                            namaWilayah = data[i].Kanwil_Name;
                        }
                    }

                    var s = '<option value="' + e + '">' + e + ' - ' + namaWilayah + '</option>';
                    s += '<option value="-1">--- Wilayah ---</option>';
                    for (var i = 0; i < data.length; i++) {
                        if (data[i].Kanwil != e.trim()) {
                            s += '<option value="' + data[i].Kanwil + '">' + data[i].Kanwil + ' - ' + data[i].Kanwil_Name + '</option>';
                        }
                    }

                    $("#WilayahDropdown").html(s);
                }
            });
        }


        function getbranch() {
            $.ajax({
                type: "GET",
                url: '@Url.Content("~/CreateAccount/getBranch")',
                data: "{}",
                success: function (data) {
                    var s = '<option value="-1">--- Branch ---</option>';
                    for (var i = 0; i < data.length; i++) {
                        s += '<option value="' + data[i].Branch + '">' + data[i].Branch + ' - ' + data[i].Branch_Name + '</option>';
                    }
                    $("#BranchDropdown").html(s);
                }
            });
        }

我应该改变哪一部分或有什么建议？谢谢

标签： javascriptjqueryasp.net-mvc