怎样从数据库中读取数据生成树？

private DataSet ds;

private SqlDataAdapter sqlDataAdapter1;

private int maxnodeid;

private void Form1_Load(object sender, System.EventArgs e)

{

string strconn=ConfigurationSettings.AppSettings["ConnStr"];

sqlConnection1 = new SqlConnection(strconn);

this.sqlConnection1.Open();

//填充DataSet

this.CreateDataSet();

//从数据库中读取数据，通过递归生成树。

InitTree(this.treeView1.Nodes,"0");

}

private void CreateDataSet()

{

this.sqlDataAdapter1=new SqlDataAdapter("select * from s_menu