试试下面的代码：
procedure LoadTree(treeDB:TDBDataSet);//初始化树
procedure UpdateTree(curNode:TTreenode;
nodeTxt:string;
state:string);//更新树
function GetNodeLevel(sFormat,sCode:string):integer;
//获得节点层数
function GetNodeItem(sCode:string):integer;//获得item
{ Public declarations }
end;
const
CTreeCodeFormat='122222';
cTreeMaxLevel=6;
CTreeRootTXT='所有图书';
var
tsgzlfrom: Ttsgzlfrom;
_err:integer;
curUser:string[10];
mystate:string;
gNodeId:string;
gNodelevel:integer;
gNode:TtreeNode;
mynode:array[0..6] of TTreenode;
i,Already,CurMode:integer;
currow:integer;
iniFile:string;
HasSub:String;
level:Integer;
implementation
uses bgNewunit;
{$R *.DFM}
procedure TtsgzlFrom.LoadTree(treeDB:TDBDataSet);//初始化树
var curID,nodeTxt:string;
level,num:integer;
begin
//初始化变量
Screen.Cursor:=crHourGlass;
tree.Enabled:=True;
tree.Items.Clear;
level:=1 ;
num:=1;
tree.items.clear;
//设置根节点
mynode[level]:=Tree.items.add(Tree.Topitem,cTreeRootTxt);
mynode[level].ImageIndex:=0;
mynode[level].SelectedIndex:=1;
//遍历数据表，利用编码字段记录排序规律，依次添加树节点
with TreeDbdo
begin
try
if not Active then
open;
first;
while not Eofdo
begin
curID:=trim(FieldByName('tsglb').AsString);
nodeTxt:=curID+'-'+trim(FieldByName('tsglbn').AsString);
level:=GetNodeLevel(cTreeCodeFormat,curID);
//这里返回代码的层次数
if level>0 then
begin
//增加下一节点时，用添加子节点的方法可轻松实现节点间的层次关系。
//注意：这里的父节点是用当前节点的上一级节点mynode[level-1]
mynode[level]:=Tree.Items.AddChild(Mynode[level-1],NodeTxt);
mynode[level].ImageIndex:=2;
mynode[level].SelectedIndex:=3;
end;
next;//下一条记录
end;
finally;
close;
end;
mynode[1].expand(False);
Screen.Cursor:=crHourGlass;
end;
end;
function TtsgzlFrom.GetNodeLevel(sFormat,sCode:string):integer;
var i,iLen:integer;
begin
level:=-1 ;
iLen:=0;
if (sFormat<>'') and (sCode<>'') then
for i:=1 to Length(sFormat)do
//分析编码格式，找出当前代码层次
begin
iLen:=iLen+StrToInt(sFormat);
if Length(sCode)=iLen then
begin
level:=i;
break;
end;
end;
result:=level;
end;
Function TtsgzlFrom.GetNodeItem(sCode:string):integer;//获得item
var i,iCount,val:integer;
tmp:string;
begin
Result:=0;
iCount:=Tree.Items.Count;
if iCount=0 then
exit;
val:=0;
for i:=1 to iCount-1do
begin
Tmp:=Tree.Items.Item.Text;
Tmp:=Copy(Tmp,0,pos('-',Tmp)-1);
if Tmp=sCode then
begin
val:=i;
Break;
end;
end;
result:=val;
end;
procedure TtsgzlFrom.UpdateTree(curNode:TTreenode;
nodeTxt:string;
state:string);
begin
if state='add' then
begin
curNode:=Tree.Items.addchild(curNode,nodeTxt);
curNode.ImageIndex:=2;
curnode.SelectedIndex:=3;
end;
if state='del' then
curNode.delete;
if state='edi' then
curNode.Text:=nodeTxt;
end;
