节点ID,父节点ID，根据节点获取该节点下所有子节点。用于点击类别查询此类别下所有商品

private string GetChildIdsById(int id)        {            List
     
       listCategory = GetDataCategory();            string ids = id.ToString();             GetChilds(id, listCategory,ref ids);             return ids;        }        private void GetChilds(int id, List
      
        listc,ref string ids)        {                       foreach (var item in listc.Where(p => Convert.ToInt32(p.FId) == id).ToList())            {                ids += "," + item.Id;                GetChilds(Convert.ToInt32(item.Id), listc,ref ids);            }                    }
      
     

　递归绑定目录（Winform)

private void BindTreeView()        {            try            {                treeView1.BeginUpdate();                treeView1.Nodes.Clear();                List
     
       listCategory = GetDataCategory();                if (listCategory.Count > 0)                {                    //绑定根目录                    ProductCategoryModel model = listCategory.Where(a => a.FId == -1).FirstOrDefault();                    if (model != null)                    {                        TreeNode rootNode = new TreeNode();                        rootNode.Text = model.Name;                        rootNode.Tag = model.Id.ToString();                        rootNode.ImageIndex = 0;                        treeView1.Nodes.Add(rootNode);                        AddNodes(rootNode, listCategory);                    }                    if (treeView1.Nodes.Count > 0)                    {                        treeView1.ExpandAll();                    }                }                treeView1.EndUpdate();            }            catch (Exception ex)            {                MessageBox.Show(ex.Message, "提示");            }        }        private static void AddNodes(TreeNode pNode, List
      
        listc)        {            pNode.Nodes.Clear();            foreach (var item in listc.Where(p => p.FId == Convert.ToInt32(pNode.Tag)).ToList())            {                TreeNode parentNode = new TreeNode();                parentNode.Text = item.Name;                parentNode.Tag = item.Id;                parentNode.ImageIndex = 1;                AddNodes(parentNode, listc);                pNode.Nodes.Add(parentNode);            }        }