树形控件的应用

 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            DataTable data = CreateDataTable();
            BindTree(data);
        }
    }
    /// <summary>
    /// 将数据绑到treeview的根节点上。
    /// </summary>
    /// <param name="tableData"></param>
    private void BindTree(DataTable tableData)
    {
        DataRow[] list = tableData.Select("ParentID='0'");
        DataRow rootRow = list[0];
        TreeNode rootNode = new TreeNode();
        rootNode.Text = rootRow["AreaName"].ToString();
        rootNode.Value = rootRow["AreaID"].ToString();
        this.TreeView1.Nodes.Add(rootNode);

        BindTreeNode(tableData, rootNode, rootNode.Value);
    }

    /// <summary>
    /// 将数据绑到TreeNode上。
    /// </summary>
    /// <param name="tableData"></param>
    /// <param name="treeNode"></param>
    /// <param name="filter"></param>
    private void BindTreeNode(DataTable tableData, TreeNode treeNode, string filter)
    {
        DataRow[] list = tableData.Select("ParentID='" + filter + "'");
        for (int i = 0; i < list.Length; i++)
        {
            TreeNode node = new TreeNode();
            node.Text = list[i]["AreaName"].ToString();
            node.Value = list[i]["AreaID"].ToString();
            treeNode.ChildNodes.Add(node);
            BindTreeNode(tableData, node, node.Value);
        }
    }

    /// <summary>
    /// 模拟数据。
    /// </summary>
    /// <returns></returns>
    private DataTable CreateDataTable()
    {
        DataTable ds = new DataTable();

        string safeSql = ConfigurationManager.ConnectionStrings["BookShopConnectionString"].ConnectionString;
        SqlConnection connBookShop = new SqlConnection(safeSql);

        string strSQL = "SELECT AreaID,AreaName,ParentID FROM dbo.T_Area WHERE Status='0'";
        SqlCommand cmd = new SqlCommand(strSQL, connBookShop);

        SqlDataAdapter da = new SqlDataAdapter(cmd);

        da.Fill(ds);
        return ds;
    }