treeview

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if(!Page.IsPostBack)
        {
            DataTable dtt = GetTreeView(0);
            foreach (DataRow dr in dtt.Rows)
            {
                TreeNode tn = new TreeNode();
                tn.Text = dr["DisplayName"].ToString();
                tn.Value = dr["NodeId"].ToString();

                //注意Convert.ToInt32对dr["NodeId"]的转换
                DataTable dttt =GetTreeView((Convert.ToInt32(dr["NodeId"])));

                foreach (DataRow drr in dttt.Rows)
                {
                    TreeNode tnn = new TreeNode();
                    tnn.Text = drr["DisplayName"].ToString();
                    tnn.Value = drr["NodeId"].ToString();
                    tn.ChildNodes.Add(tnn);
                }

                TreeView1.Nodes.Add(tn);
            }
       
       
        }

    }
    public DataTable GetTreeView(int nodeId)
    {
        SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=111111;database=GameCardSale");
        string sql = "select * from Sysfun where parentNodeId='"+nodeId+"'";
        SqlDataAdapter da = new SqlDataAdapter (sql,conn);
        DataSet ds = new DataSet ();
         da.Fill(ds);
         return ds.Tables[0];
   
    }
}