kendo的下拉框树示例

        public static string GetTreeJson_kendo(List<Category>  list)
        {
        
            List<TreeNode_kendo> list_return = new List<TreeNode_kendo>();
        
            var top = list.Where(a => a.Pid == 0);
            foreach (var item in top)
            {
                TreeNode_kendo node = new TreeNode_kendo()
                {
                    id = item.Id, 
                    caname = item.CaName, 
                };
                DiGuiAdd_kendo(node, list);

                list_return.Add(node);
            }
            return Newtonsoft.Json.JsonConvert.SerializeObject(list_return);
        }

        private static void DiGuiAdd_kendo(TreeNode_kendo node, List<Category> list)
        {
            var sub = list.Where(a => a.Pid == node.id);
            if (sub.Count() == 0)
            {
                return;
            }
            List<TreeNode_kendo> list_sub = new List<TreeNode_kendo>();
            foreach (var item2 in sub)
            {
                TreeNode_kendo node2 = new TreeNode_kendo()
                {
                    id = item2.Id, 
                    caname = item2.CaName, 
                };
                DiGuiAdd_kendo(node2, list);
                list_sub.Add(node2);
            }
            node.items = list_sub;
        }

<input type="text" name="dropdowntree" id="dropdowntree" />
                @Html.HiddenFor(a => a.CaId)
  
<script src="/js/jquery.min.js"></script>              
<!--kendoui-->
<link href="/kendo/styles/kendo.common.min.css" rel="stylesheet">
<link href="/kendo/styles/kendo.rtl.min.css" rel="stylesheet">
<link href="/kendo/styles/kendo.default.min.css" rel="stylesheet">
<link href="/kendo/styles/kendo.default.mobile.min.css" rel="stylesheet">
<script src="/kendo/js/kendo.all.min.js"></script>
<script>
   var dropdowntree;
    $(function () {
        $("#dropdowntree").kendoDropDownTree({
            placeholder: "选择分类...",
            height: "auto",
            dataTextField: "caname",
            dataValueField: "id",
            dataSource: @Html.Raw(ViewBag.treejson_kendo)
                });
        dropdowntree = $("#dropdowntree").data("kendoDropDownTree");

        var caid = $('#CaId').val();
        if (caid != undefined) {
            dropdowntree.value(caid);  //取值时用      dropdowntree.value();
        }
    })
</script>