那位高手能给我实现以下树的添加、删除节点功能？

那位高手能给我实现以下树的添加、删除节点功能？
1。
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StdCtrls, DB, ADODB, Mask, DBCtrls, ExtCtrls;type
  TForm1 = class(TForm)
    TreeView1: TTreeView;
    ADOConnection1: TADOConnection;
    ADOTable1: TADOTable;
    new: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    procedure FormCreate(Sender: TObject);
    procedure newClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
   function loadcode(treeDB:TADOTable):integer;
   function getlevel(sformat,scode:string):integer;
    { Public declarations }
  end;var
  Form1: TForm1;
  tv:ttreenode;const
  scodeformat = '322222';  //科目代码结构
  sfirstnodetxt = '科目代码';  //首节点显示的文字implementation{$R *.dfm}function tform1.loadcode(treeDB:TADOTable):integer;
var
  nowid,sname,showtxt:string;
  i,level:integer;
  mynode:array[0..6]of ttreenode;
begin
  screen.cursor:=crhourglass;
  level:=0;
  with treeDB do
  begin
    try
    if not active then open;
    first;
    TreeView1.items.clear;
    mynode[level]:=TreeView1.items.add(TreeView1.topitem,sfirstnodetxt);
    mynode[level].imageindex:=0;
    mynode[level].selectedindex:=0;
    while not eof do
    begin
      nowid:=trim(fieldbyname('acode').asstring);
      showtxt:=nowid+'------------'+fieldbyname('aname').asstring;
      level:=getlevel(scodeformat,nowid);
      if level> 0 then
      begin
        mynode[level]:=TreeView1.items.addchild(mynode[level-1],showtxt);
        mynode[level].imageindex:=1;
        mynode[level].selectedindex:=2;
      end;
      next;
    end;
    finally
      close;
    end;
  end;
  mynode[0].expand(false);
  screen.cursor:=crdefault;
end;function tform1.getlevel
(sformat,scode:string):integer;
var i,level,ilen:integer;
begin
level:=-1;
ilen:=0;
if (sformat<>'')and(scode<>'')then
for i:=1 to length(sformat) do
begin
ilen:=ilen+strtoint(sformat[i]);
if length(scode)=ilen then
begin
  level:=i;
  break;
end;
end;
result:=level;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
with ADOTable1 do
begin
open;
indexfieldnames:='acode'; 
end;
loadcode(ADOTable1);
end;2。
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StdCtrls, DB, ADODB, Mask, DBCtrls, ExtCtrls, Menus;
const
 cTreeCodeFormat='122222';
 cTreeMaxLevel=6;
 cTreeRootTxt='单位字典';type
  TForm1 = class(TForm)
    TreeView1: TTreeView;
    ADOConnection1: TADOConnection;
    ADOTable1: TADOTable;
    DataSource1: TDataSource;
    DBEdit1: TDBEdit;
    DBEdit2: TDBEdit;
    Button1: TButton;
    PopupMenu1: TPopupMenu;
    Add1: TMenuItem;
    Delete1: TMenuItem;
    Edit1: TMenuItem;
    procedure FormCreate(Sender: TObject);
    procedure Add1Click(Sender: TObject);
    procedure Delete1Click(Sender: TObject);
    procedure Edit1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    procedure LoadTree(treeDB:TADOTable);
    procedure UpdateTree(curNode:TTreenode;nodeTxt:string;state:string);
    function  GetNodeLeveL(sFormat,sCode:string):integer;
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}function TForm1.GetNodeLeveL(sFormat,scode:string):integer;
var i,level,iLen:integer;
begin
  level:=-1;
  iLen:=0;
  if (sFormat<>'') and (sCode<>'') then
    for i:=1 to length (sformat) do
    begin
      iLen:=iLen+StrToInt(sFormat[i]);
      if length(sCode)=iLen then
      begin
        level:=i;
        break;
      end;
    end;
  result:=level;
end;procedure TForm1.LoadTree(treeDB:TADOTable);
var
  curID,nodeTxt:string;
  level:integer;
  mynode:array[0..6] of TTreenode;
begin
  TreeView1.Enabled:=true;
  TreeView1.Items.clear;
  level:=0;
  TreeView1.items.clear;
  mynode[level]:=TreeView1.Items.add(TreeView1.Topitem,cTreeRootTxt);
  mynode[level].ImageIndex :=1;
  with TreeDB DO
  begin
    try
    if not Active then open;
    first;
    while not Eof do
    begin
       curID:=trim(FieldByName('code').Asstring);
       nodeTxt:=curID+'-'+trim(FieldByName('name').Asstring);
       level:=GetNodelevel(cTreeCodeFormat,curID);
       if level>0 then
       begin
         mynode[level]:=TreeView1.items.addchild(mynode[level-1],nodeTxt);
         mynode[level].imageIndex:=2;
       end;
          next;
    end;
  finally;
    close;
  end;
  mynode[0].expand(true);
 end;
end;procedure TForm1.UpdateTree(curNode:TTreenode;nodeTxt:string;state:string);
 begin
  if state='add' then
  begin
    curNode:=TreeView1.items.addchild(curNode,nodeTxt);
    curNode.imageIndex:=2;
  end;
  if state='del' then curNode.delete;
  if state='edi' then curNode.text:=NodeTxt;
 end;procedure TForm1.FormCreate(Sender: TObject);
begin
 with ADOTable1 do
 begin
   open;
   indexFieldNames:='code';
   active:=true;
 end;
  LoadTree(ADOTable1);
end;