protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            CreateTreeNode();
        }
    }

  
    public void CreateTreeNode()
    {
        TreeNode mainNode = new TreeNode();
        mainNode.Text = "所有";

        IList<string> list = new List<string>(){"aa","bb","cc"};
        foreach (string value in list)
        {
            string aaCount =GetTable(string.Format(@"select .... where  tname='{0}'",value)).Rows[0][0].ToString();
            TreeNode node = new TreeNode();
            node.Text = value + "(" + aaCount + ")";
            mainNode.ChildNodes.Add(node);
        }
        TreeView1.ShowLines = true;
        TreeView1.Nodes.Add(mainNode);
    }
    public DataTable GetTable(string str)
    {
        //自己实现
    }