数据库商品类设计（ID、类名、父类ID）遍历添加到TreeView中

ID	类别	父类别
1	A	0
2	B	0
3	C	0
4	AA	1
5	BB	2
6	CC	3

添加到TreeView中：

 1 type
 2   PpgInfo = ^TpgInfo;
 3 
 4   TpgInfo = record
 5     aName: string;
 6     aID: string;
 7     aPID: string;
 8   end;
 9 
10 //add to tv
11 procedure TForm2.add2tv(al: TList<TpgInfo>);
12 var
13   paRec: PpgInfo;
14   i: Integer;
15   find: Boolean;
16 begin
17   while al.Count > 0 do
18   begin
19 
20     if al[0].aPID = '0' then
21     begin
22       // add tv
23       New(paRec);
24       paRec^ := al[0];
25       TreeView1.Items.AddObject(TreeView1.Items.GetFirstNode,
26         al[0].aName, paRec);
27       al.Delete(0);
28     end
29     else
30     begin
31       // search pid
32       find := False;
33       for i := 0 to TreeView1.Items.Count - 1 do
34       begin
35         if PpgInfo(TreeView1.Items[i].Data).aID = al[0].aPID then
36         begin
37           New(paRec);
38           paRec^ := al[0];
39           TreeView1.Items.AddChildObject(TreeView1.Items.Item[i],
40             paRec.aName, paRec);
41           al.Delete(0);
42           find := True;
43           Break;
44         end;
45       end;
46       if not find then
47       begin
48         al.Add(al[0]);
49         al.Delete(0);
50       end;
51 
52     end;
53   end;
54 end;
55 
56 //测试数据
57 procedure TForm2.Button2Click(Sender: TObject);
58 var
59   arrList: TList<TpgInfo>;
60   aRec: TpgInfo;
61 begin
62   arrList := TList<TpgInfo>.Create;
63   aRec.aName := 'A';
64   aRec.aID := '1';
65   aRec.aPID := '0';
66   arrList.Add(aRec);
67   aRec.aName := 'B';
68   aRec.aID := '2';
69   aRec.aPID := '0';
70   arrList.Add(aRec);
71   aRec.aName := 'C';
72   aRec.aID := '3';
73   aRec.aPID := '0';
74   arrList.Add(aRec);
75   aRec.aName := 'AA';
76   aRec.aID := '4';
77   aRec.aPID := '1';
78   arrList.Add(aRec);
79   aRec.aName := 'BB';
80   aRec.aID := '5';
81   aRec.aPID := '2';
82   arrList.Add(aRec);
83   add2tv(arrList);
84   FreeAndNil(arrList);
85 end;
86 //别忘了释放
87   if Assigned(TreeView1) then
88     for i := 0 to TreeView1.Items.Count - 1 do
89         Dispose(PpgInfo(TreeView1.Items[i].Data));

效果图：

算法效率比较低～