layui获取树形菜单所有选中的值

        layui.use(['form', 'layedit', 'laydate','tree','util'], function() {
            var form = layui.form,
                layer = layui.layer,
                tree = layui.tree,
                util = layui.util;

            //开启复选框
            tree.render({
                elem: '#test7'
                ,data: getData()
                ,showCheckbox: true
                ,id: 'id'
                // ,oncheck: function(obj){
                //     console.log(obj.data); //得到当前点击的节点数据
                //     console.log(obj.checked); //得到当前节点的展开状态：open、close、normal
                //     console.log(obj.elem); //得到当前节点元素
                // }
            });

            //监听提交
            form.on('submit(form_commit)', function(data) {
                //获得选中的节点
                
                var checkData = tree.getChecked('id');

                var list = new Array();

                list = getChecked_list(checkData);

                console.log(checkData)

                console.log(list);

            });


            // 获取选中节点的id
            function getChecked_list(data) {
                var id = "";
                $.each(data, function (index, item) {
                    if (id != "") {
                        id = id + "," + item.id;
                    }
                    else {
                        id = item.id;
                    }
                    var i = getChecked_list(item.children);
                    if (i != "") {
                        id = id + "," + i;
                    }
                });
                return id;
            }

        });