1,
SqlDataReader dr = comm.ExecuteReader();
   //循环dr,给dListParent添加条目
   while(dr.Read())
   {
      dListChild.Items.Add(new ListItem(dr[1].ToString(),dr[0].ToString()));
    //也可以这样
    //dListParent.Items.Add(new ListItem(dr["phone_text"].ToString(),dr["phone_value"].ToString()));
   }

这样绑定效能高点,且灵活的添加特殊的条目如在while前加:
dListChild.Items.Add(new ListItem("全部选择","0"));

2,
SqlDataAdapter myAdapter = new SqlDataAdapter(myCommand);
     DataTable dt = new DataTable();
     myAdapter.Fill(dt);

     // 数据绑定 DropDownList 控件
     DropDownList1.DataSource = dt;
     DropDownList1.DataTextField = "ProductName";
     DropDownList1.DataValueField = "UnitPrice";
     DropDownList1.DataBind();