动态添加treeview

 private void bindtreeview()
    {
        this.TreeView1.Nodes.Clear();
        string strsql = "select * from title,detitle where title.title_id=detitle.title_id";
        DataSet ds = DB.ds(strsql);
        this.ViewState["DataSet_Tree"] = ds;
        addtree(0, (TreeNode)null);
    }

    public void addtree(int ParentId, TreeNode pnode)
    {
        DataSet DataSet_Tree = (DataSet)this.ViewState["DataSet_Tree"];
        DataView DataView_Tree = new DataView(DataSet_Tree.Tables[0]);
        DataView_Tree.RowFilter = "title_id=" + ParentId;
        foreach (DataRowView row in DataView_Tree)
        {
            TreeNode Node = new TreeNode();
            if (pnode == null)
            {
                Node.Text = row["title_name"].ToString();
                Node.Value = row["title_id"].ToString();
                this.TreeView1.Nodes.Add(Node);
                Node.Expanded = true;//展开当前节点
                addtree(Int32.Parse(row["title_id"].ToString()), Node);
            }
            else
            {
                Node.Text = row["detitle_name"].ToString();
                Node.Value=row["detitle_id"].ToString();
                pnode.ChildNodes.Add(Node);
                Node.Expanded = true;
                addtree(Int32.Parse(row["detitle_id"].ToString()), Node);
            }
        }