jquery easyui 反复加载


当我点击 末端子节点，又把整个树给加载一遍（在程序里边设置断点，又执行了一遍），加载到末端子节点，怎么样才能避免？谢谢！！
@{
    ViewBag.Title = "我看过的";
    Layout = "~/Views/Shared/_Admin.cshtml";
}@section Header{
<link rel="stylesheet" type="text/css" href="/Scripts/easyui/themes/default/easyui.css">  
<link rel="stylesheet" type="text/css" href="/Scripts/easyui/themes/icon.css">  
<script type="text/javascript" src="/Scripts/easyui/jquery.easyui.min.js"></script>  
<script type="text/javascript">
$(function () {
    LoadTree(); 
});
 
function LoadTree() {
    $('#tree').tree({
        checkbox: true,
        lines:true,
        url: '/UserManage/GetTreeViewData'
    });
}
</script>
}
<h1 class="title">
    我看过的</h1>  <div region="west" split="true" title="影视分类" style="width:200px;padding:10px;">
   <ul id="tree"></ul>
  </div>action        public JsonResult GetTreeViewData()
        {
            return Json(RegisteredUserBLL.GetUserTree());
        }
bll        public static List<TreeView> GetUserTree()
        {
            using (var db = new WEBVODEntities())
            {
                var list = db.RegisteredUsers.Include("Department").OrderBy(a => a.Department.Name)
                    .ThenBy(a => a.RealName).ToList();
                int deptId = 0;
                List<TreeView> treeList = new List<TreeView>();
                TreeView treeRoot = new TreeView(0,"全员职工","open",null);
                TreeView treeDept = null;
                TreeView treeUser = null;                treeList.Add(treeRoot);
                if (list.Count > 0)
                    treeRoot.children = new List<TreeView>();                foreach (RegisteredUsers user in list)
                {                    if (user.DepartmentId != deptId)
                    {
                        deptId = (int)user.DepartmentId;
                        treeDept = new TreeView(-(int)user.DepartmentId, user.Department.Name, "closed", new List<TreeView>());
                        treeRoot.children.Add(treeDept);                        treeUser = new TreeView(user.Id, user.RealName, "closed", null);
                        treeDept.children.Add(treeUser);
                    }
                    else
                    {
                        treeUser = new TreeView(user.Id, user.RealName, "closed", null);
                        treeDept.children.Add(treeUser);
                    }
                }                return treeList;            }
        }