使用Ajax实现层叠多选择列表框

我使用MVC4，我试图将级联列表框实现到我的一个视图中，我一直遵循本教程，并成功创建了2个级联下拉框，但我现在需要相同类型的功能，用户可以选择多个项目的列表框。

只是为了澄清用户将能够从下拉列表中选择威胁。

在选择威胁时，将会出现一个列表框，其中包含所选威胁的相关安全事件，在这里用户可以选择多个安全事件或单个安全事件

在选择他们所选择的安全事件后，另一个列表框将填充与所选安全事件相关联的任何控件。

这是我到目前为止写的

 public class AddNewRiskVM
    {
        public SelectList RiskTypeList { get; set; }
        public SelectList GroupMembersList { get; set; }
        public SelectList ThreatsList { get; set; }
        public SelectList SecurityEventsList { get; set; }
        public List<int> SelectedSecurityEventsIDs { get; set; }
        public SelectList ISOControlList { get; set; }
        public List<int> AssociatedIsoIDs { get; set; }
        public int ISOControlID { get; set; }
        public AddNewRiskVM()
        {
            SelectedSecurityEventsIDs = new List<int>();
            AssociatedIsoIDs  = new List<int>();
        }       
    }

public void ConfigureNewRisk(AddNewRiskVM ViewModel)
        { 
            var RiskTypes = _DBContext.RiskTypes;
            var Threats = _DBContext.Threats;
            ViewModel.RiskTypeList = new SelectList(RiskTypes, "ID", "Description");
            ViewModel.GroupMembersList = new SelectList(new List<GroupMember>(), "ID", "Name");
            ViewModel.ThreatsList = new SelectList(Threats, "ID", "Description");
            ViewModel.SecurityEventsList = new SelectList(new List<SecurityEvent>(), "ID", "Description");
            ViewModel.ISOControlList = new SelectList(new List<ISOControl>(), "ID", "Description");
        }
        public ActionResult AddNewRisk()
        {
            AddNewRiskVM ViewModel = new AddNewRiskVM();
            ConfigureNewRisk(ViewModel);
            return View(ViewModel);
        }
     public IEnumerable<ISOControl> GetISOControls(int SecurityEventID)
        {
            var QueryResults = _DBContext
                                   .SecurityEventHasISOControls
                                   .Include("SecurityEventHasISOControls.ISOControlID")
                                   .Where(x => x.SecurityEventID == SecurityEventID)
                                   .Select(x => x.ISOControl);
            return QueryResults;
        }
        public JsonResult GetJsonISOControl(int ID)
        {
            var ISOControlListT = this.GetISOControls(Convert.ToInt32(ID));
            var ISOControlList = ISOControlListT.Select(x => new SelectListItem()
            {
                Text = x.Description,
                Value = x.ID.ToString(),
            });
            return Json(ISOControlList, JsonRequestBehavior.AllowGet);
        }

注意-我有类似的方法GetISOControl &GetJsonControl，用于SecurityEvent

<div class="containeSelect">
     @using (Html.BeginForm(null, null, new { @id = string.Empty }, FormMethod.Post, new { @id = "AddNewWithSelect" }))
     {
        <h3>Add New Risk</h3>
        <fieldset>
             @Html.DropDownList("RiskType", Model.RiskTypeList, "Select Risk Type", htmlAttributes: new { @class = "CascadeInputBox", onchange = "GetMembers()"})
             @Html.DropDownList("GroupMember", Model.GroupMembersList, "Select Group Member", htmlAttributes: new {@class = "CascadeInputBox", @id = "CascadeDropDownList2"})
             @Html.DropDownList("Threats", Model.ThreatsList, "Select Threat", htmlAttributes: new { @class = "CascadeInputBox", onchange = "GetSecurityEvents()"})
             @Html.ListBoxFor(m => m.SelectedSecurityEventsIDs, Model.SecurityEventsList, htmlAttributes: new { @id = "SelectListEvent", onchange = "GetISOControls()"})
             @Html.ListBox("ISOControls", Model.ISOControlList, htmlAttributes: new { @id = "SelectListISO"})
        </fieldset>
     }
<script>
    function GetISOControls() {
        $.ajax({
            url: "@Url.Action("GetJsonISOControl", "RiskAssesment")",
            dataType: "json",
            type: "GET",
            data: { id: $("#Events").val() },
            error: function () {
            },
            beforeSend: function () {
            },
            success: function (data) {
                var items = "";
                $.each(data, function (i, item) {
                    items += "<option value='"" + item.Value + "'">" + item.Text + "</option>";
                });
                $("#SelectListISO").html(items);
            }
        });
    }
 </script>
<script>  
    function GetSecurityEvents() {
        $.ajax({  
            url: "@Url.Action("GetJsonSecurityEvent", "RiskAssesment")", 
            dataType: "json",  
            type: "GET",  
            data: { id: $("#Threats").val() },
            error: function () {  
            },  
            beforeSend: function () {  
            },  
            success: function (data) {  
                var items = "";  
                $.each(data, function (i, item) {  
                    items += "<option value='"" + item.Value + "'">" + item.Text + "</option>";  
                });
               $("#SelectListEvent").html(items);
            }  
        });         
    }  
 </script> 

data: { id: $("#Events").val() },