无法在选择的MultiselectList中加载保存的值

Question

您好，我是使用ListBox MultiSelectList的新手，我的问题是我无法获取页面的onload值，这是我的代码

在“我的控制器”中初始化下拉值

var getddlName = (from a in nameList
                                      where a.personId != null
                                      && a.personId != 0
                                      select new SelectListItem
                                      {
                                          Value = a.personId.ToString(),
                                          Text = a.personFullname
                                      }).ToList();
            ViewBag.ddlNameList = getddlName;

要获取保存的值并在加载时加载它

if (ddlPersonIds != null)
            {
                List<string> list1 = new List<string>();
                var empIds = ddlPersonIds.Split(',');
                foreach(var c in empIds){

                list1.Add(c);
                }

               ViewBag.ddlPersonName = list1;

            }

在我的视图中，这是如何将值传递给MultiselectList

我在HTML头中创建了变量容器

var ddlNameList = ViewBag.ddlNameList;
var ddlPersonName = ViewBag.ddlPersonName;

和我的MultiselectList

<div class="editor-field">


 @Html.ListBox("PersonIds", new MultiSelectList(ddlNameList, "Value", "Text", ddlPersonName), new { data_placeholder = "Select Employees...", @class = "chosen input-long-75", multiple = "multiple" })
                            </div>

编辑：即使我在ddlPersonName中获得了该值，也无法显示并在ddlNameList中被选择

谢谢