本文实例讲述了asp.net实现递归方法取出菜单并显示在DropDownList中的方法。分享给大家供大家参考，具体如下：
树形栏目展示以DropDownList的形式显示出来。
protected void Page_Load(object sender, EventArgs e){ if (!IsPostBack) { DataTable table = bllSite.GetChannelNames(CurrentUser.ParkID); BindChannelType(table, 0, 0); }}//递归方法取private void BindChannelType(DataTable dt, int categoryid, int layer){ DataView dv = new DataView(dt); dv.RowFilter = " Pid= " + categoryid.ToString(); //过滤 if (categoryid != 0) { layer++; //默认为第一层 } foreach (DataRowView drv in dv) { string span = ""; if (categoryid != 0) { for (int i = 0; i < layer; i++)//父级菜单不缩进 { span += " "; } span += "└"; } ListItem li = new ListItem(); li.Text = span + drv["ChannelName"].ToString(); li.Value = drv["Id"].ToString(); this.ddlChannel.Items.Add(li); BindChannelType(dt, Convert.ToInt32(drv["Id"]), layer); }} 
