仅在扩展节点时加载树节点

Question

i有一个ASP.NET树视图控件，该控件在页面加载上加载树数据。下面给出的代码：

protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                DocEng.TreeProvider cmsTree = new DocEng.TreeProvider(MembershipContext.AuthenticatedUser);
                var node = cmsTree.SelectSingleNode(SiteContext.CurrentSiteName, "/", "en-US");
                DocEng.TreeNodeCollection myChildren = node.AllChildren;
                IEnumerable<DocEng.TreeNode> TreeNodes = myChildren.AsEnumerable<DocEng.TreeNode>();
                foreach (var tree in TreeNodes.Where(x => x.NodeLevel == 0))
                {
                    System.Web.UI.WebControls.TreeNode ParenTreeNode = new System.Web.UI.WebControls.TreeNode();
                    ParenTreeNode.Text = tree.NodeID.ToString() + ". " + SiteContext.CurrentSiteName;
                    ParenTreeNode.Value = tree.NodeID.ToString();
                    AddNodes(ParenTreeNode);
                    tvContentTree.Nodes.Add(ParenTreeNode);
                }
            }
        }

  /// <summary>
        /// Adding child for the parent 
        /// </summary>
        /// <param name="TreeNode"></param>
        private void AddNodes(System.Web.UI.WebControls.TreeNode TreeNode)
        {
            DocEng.TreeProvider cmsTree = new DocEng.TreeProvider(MembershipContext.AuthenticatedUser);
            var node = cmsTree.SelectSingleNode(SiteContext.CurrentSiteName, "/", "en-US");
            DocEng.TreeNodeCollection myChildren = node.AllChildren;
            IEnumerable<DocEng.TreeNode> childTreeNodes = myChildren.AsEnumerable<DocEng.TreeNode>();
            foreach (var childTree in childTreeNodes.Where(x => x.NodeParentID == Convert.ToInt32(TreeNode.Value)))
            {
                System.Web.UI.WebControls.TreeNode ChildNode = new System.Web.UI.WebControls.TreeNode();
                ChildNode.Text = childTree.NodeID.ToString() + ". " + childTree.DocumentName.ToString();
                ChildNode.Value = childTree.NodeID.ToString();
                TreeNode.ChildNodes.Add(ChildNode);
                AddNodes(ChildNode);
                if (childTree.NodeLevel == 1)
                    ChildNode.Collapse();
            }
        }

我需要重写此代码，仅在扩展节点时才加载数据。此外，在我们展开时，数据只能填充到点击节点及其子女直到结束。

Answer 1

尝试在页面载上仅获取节点的第一个级别，并添加一个空的子节点，只是为了使其可扩展。

扩展后，删除此儿童节点并与普通儿童填充。