动态绑定TreeVew

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    private DataView dv;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            GetData();
            BuilderTree(-1, (TreeNode)null);
        }
    }

    private void GetData()
    {
        string sql = "select * from inventoryclass";
        DataSet ds = DBHelper.GetData(sql);
         dv = new DataView(ds.Tables[0]);
    }

    //树的绑定
    private void BuilderTree(int ParentID, TreeNode pNode)
    {
        TreeView1.ShowCheckBoxes = TreeNodeTypes.All;
        dv.RowFilter = "ParentID =" + ParentID;
        foreach (DataRowView row in dv)
        {
            TreeNode node = new TreeNode();
            if (pNode == null)
            {
                //添加根节点
                node.Text = row["name"].ToString();
                TreeView1.Nodes.Add(node);
                node.Expanded = true;
                BuilderTree(int.Parse(row["id"].ToString()), node); //递归
            }
            else
            {
                //添加当前节点的子节点
                node.Text = row["name"].ToString();
                pNode.ChildNodes.Add(node);
                node.Expanded = true;
                BuilderTree(int.Parse(row["id"].ToString()), node); //递归
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.Data.SqlClient;

/// <summary>
///DBHelper 的摘要说明
/// </summary>
public class DBHelper
{
    public DBHelper()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }

    public static DataSet GetData(string sql)
    {
        try
        {
            SqlConnection conn = new SqlConnection(@"server=(local);database=db_13;uid=sa;pwd=13875712605;");

            //SqlCommand cmd = new SqlCommand(sql,conn);
            conn.Open();
            SqlDataAdapter da = new SqlDataAdapter(sql,conn);

            DataSet ds = new DataSet();

            da.Fill(ds);
            conn.Close();
            return ds;
        }
       catch(Exception e)
        {
            throw new Exception("连接错误");
        }

    }
}