真正的对treeview实行动态绑定

只有点击Node的是才进行绑定：

 

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
    string connstr = ConfigurationManager.AppSettings["ConnString"].ToString();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            TreeBind();
        }  
    }
    protected void TreeBind()
    {
        SqlConnection conn = new SqlConnection(connstr);
        string sql = "select distinct(bsf),bt from dbo.ZYJHYSJ where fjh='00000000000'";
        SqlCommand comm = new SqlCommand(sql, conn);
        conn.Open();
        SqlDataReader dr = comm.ExecuteReader();
        while (dr.Read())
        {
            TreeNode node = new TreeNode(dr["bt"].ToString(), dr["bsf"].ToString());
            CreateChildTree(node, dr["bsf"].ToString());  //得到子节点 
            TreeView1.Nodes.Add(node);

        }
    }
   public void CreateChildTree(TreeNode parentNode, string parentID)
    {
        SqlConnection conn = new SqlConnection(connstr);
        string sql = "select distinct(bsf),bt from dbo.ZYJHYSJ where fjh=@rootID";
        SqlCommand comm = new SqlCommand(sql, conn);
        comm.Parameters.Add("@rootID", SqlDbType.NVarChar).Value = parentID;
        conn.Open();
        SqlDataReader dr = comm.ExecuteReader();
        while (dr.Read())
        {
            TreeNode node = new TreeNode(dr["bt"].ToString(), dr["bsf"].ToString());
            parentNode.ChildNodes.Add(node);
        }

    }
  
    protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
    {  

        //TreeNode parentNode = TreeView1.SelectedNode;
        //string parentID = TreeView1.SelectedValue.ToString();

        //if (parentNode.Depth <= 2)
        //{
        //    parentNode.ChildNodes.Clear();
        //    CreateChildTree(parentNode, parentID);
        //}
   
    }

    protected void TreeView1_TreeNodeExpanded(object sender, TreeNodeEventArgs e)
    {
        if (e.Node.Depth <= 1)
        {
            foreach (TreeNode Tn in e.Node.ChildNodes)
            {
                CreateChildTree(Tn, Tn.Value);
            }
        }

    }
    protected void TreeView1_TreeNodeCollapsed(object sender, TreeNodeEventArgs e)
    {
        if (e.Node.Depth <= 1)
        {
            foreach (TreeNode Tn in e.Node.ChildNodes)
            {
                Tn.ChildNodes.Clear();
                Tn.Collapse();
            }
        }
    }