TreeView保存当前节点展开状态【Draft Saved】

前台没有什么而设置，主要代码实现都是在后台。包括加载节点数据，保存当前节点Parent路径状态，设置当前节点展开状态。

Form_Load中：首先获取到保存的state状态，去遍历treeview所有节点，匹配。如果匹配成功，设置该节点Expended属性为true。

【图中Highlight部分，换成递归遍历更好，暂时没有实现。】

 protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                BindHowNode();
                BindReportNode();
                BindDocNode();
                BindLinksNode();
            }
            if (Request.QueryString["state"] != null)
            {
                string state = Request.QueryString["state"].ToString();
                foreach (TreeNode tn in tvAcc.Nodes)
                {
                    if (tn.Text == state)
                    {
                        tn.Expanded = true;
                    }

                    foreach (TreeNode tn1 in tn.ChildNodes)
                    {
                        if (tn1.Text == state)
                        {
                            tn1.Expanded = true;
                        }

                        foreach (TreeNode tn2 in tn1.ChildNodes)
                        {
                            if (tn2.Text == state)
                            {
                                tn2.Expanded = true;
                            }
                        }
                    }
                }
            }
        }

 

后台动态加载TreeView数据：

       private void BindHowNode()
        {
            TreeNode rootHow = new TreeNode("How We Work", "How We Work", "", "#", "");
            rootHow.Expanded = false;
            tvAcc.Nodes.Add(rootHow);

            HowBLL howBLL = new HowBLL();
            DataTable dtHow = new DataTable();
            dtHow = howBLL.GetItems();

            for (int i = 0; i < dtHow.Rows.Count; i++)
            {
                string itemID = dtHow.Rows[i]["ID"].ToString();
                string itemTitle = dtHow.Rows[i]["itemTitle"].ToString();
                TreeNode treeDoc = new TreeNode(itemTitle, "HowWeWork.aspx?hid=" + itemID, "", "", "");
                rootHow.ChildNodes.Add(treeDoc);
            }
        }

在SelectedNodeChanged()事件中添加当前状态的值：
（此处用的是TreeNode.Text, 而没用TreeeNode.ValuePath，因为Value值用来页面跳转了，与treeview的路径有一定出入。）

        protected void tvAcc_SelectedNodeChanged(object sender, EventArgs e)
        {
            TreeNode tn = tvAcc.SelectedNode.Parent;

            if (Request.QueryString["state"] != null)
            {
                tn.Expanded = true;
            }
            string navUrl = tvAcc.SelectedNode.Value.ToString() + "&state=" + tn.Text;
            Response.Redirect(navUrl);
        }

 

转载于:https://www.cnblogs.com/eva_2010/archive/2012/06/15/2550697.html