树形结构

 

private void Page_Load(object sender, System.EventArgs e)
        {
            // 定义数据库连接
            SqlConnection CN = new SqlConnection();
            try 
            {
                //初始化连接字符串
                CN.ConnectionString=
                "data source=pmserver;initial catalog=Benchmark;persist security info=False;user id=sa;Password=sa;";
                CN.Open();

                SqlDataAdapter adp = new SqlDataAdapter("select * from tbTree",CN);
                DataSet ds=new DataSet();
                adp.Fill(ds);
                this.ViewState["ds"]=ds; 
            }
            catch (Exception ex)
            {
                Session["Error"] = ex.ToString();
                Response.Redirect("error.aspx");       //̀跳转程序的公共错误处理页面
            }
            finally 
            {
                CN.Close();
            }
            //调用递归函数，完成树形结构的生成
            AddTree(0, (TreeNode)null);
        }

        //递归添加树的节点
        public void AddTree(int ParentID,TreeNode pNode) 
        {
            DataSet ds=(DataSet) this.ViewState["ds"]; 
            DataView dvTree = new DataView(ds.Tables[0]);
            //过滤ParentID,得到当前的所有子节点
            dvTree.RowFilter =  "[PARENTID] = " + ParentID;

            foreach(DataRowView Row in dvTree) 
            {
                TreeNode Node=new TreeNode() ;
                if(pNode == null) 
                {    //添加根节点
                    Node.Text = Row["ConText"].ToString();
                    TreeView1.Nodes.Add(Node);
                    Node.Expanded=true;
                    AddTree(Int32.Parse(Row["ID"].ToString()), Node);    //再次递归
                } 
                else 
                {   //̀添加当前节点的子节点
                    Node.Text = Row["ConText"].ToString();
                    pNode.Nodes.Add(Node);
                    Node.Expanded = true;
                    AddTree(Int32.Parse(Row["ID"].ToString()),Node);     //再次递归
                }
            }                   
        }