树

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, DB, ADODB, StdCtrls, ComCtrls, Grids, DBGrids;

type
PNodeRec=^TNodeRec;
TNodeRec=record
id: string;
name: string;
pid: string;
end;

TForm1 = class(TForm)
TreeView1: TTreeView;
ADOQuery1: TADOQuery;
Memo1: TMemo;
DataSource1: TDataSource;
ADOQuery2: TADOQuery;
DBGrid1: TDBGrid;
ADOConnection1: TADOConnection;
procedure FormCreate(Sender: TObject);
procedure TreeView1Change(Sender: TObject; Node: TTreeNode);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure MakeTree(Query: TADOQuery; TreeView: TTreeView);
var
List: TStringList;
Node: TTreeNode;
Index: Integer;
PNode: PNodeRec;
begin
TreeView.Items.BeginUpdate;
try
TreeView.Items.Clear;
List := TStringList.Create;
try
List.Sorted := True;
Query.First;
while not Query.Eof do
begin
PNode:= new(PNodeRec);
PNode^.id := Query.fieldbyname('ID').AsString;
PNode^.name := Query.fieldbyname('Name').AsString;
PNode^.pid := Query.fieldbyname('ParentID').AsString;
if Query.FieldByName('ParentID').AsInteger = 0 then // ParentID=0，root node
Node := TreeView.Items.AddChild(nil, Query.FieldByName('Name').AsString)
else
begin
Index := List.IndexOf(Query.FieldByName('ParentID').AsString);
Node := TreeView.Items.AddChild(TTreeNode(List.Objects[Index]),
Query.FieldByName('Name').AsString);
end;
Node.Data := PNode;
List.AddObject(Query.FieldByName('ID').AsString, Node);
Query.Next;
end;
finally
List.Free;
end;
finally
TreeView.Items.EndUpdate;
end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
Memo1.Clear;
MakeTree(ADOQuery1, TreeView1);
end;

procedure TForm1.TreeView1Change(Sender: TObject; Node: TTreeNode);
var
s: string;

function blNode(aNode: TTreeNode): string;
var
childnode: TTreenode;
i: Integer;
begin
result := ''''+ PNoderec(Node.Data)^.id+''''+',';
for i :=0 to aNode.Count -1 do
begin
childnode := aNode.Item[i];
Result := Result +''''+PNoderec(childnode.Data)^.id+''''+',';
if childnode.Count >0 then
blNode(childnode);
end;
Result := Copy(Result, 1, Length(Result)-1);
end;
begin
Memo1.Clear;
Memo1.Lines.Add('id: '+PNoderec(Node.Data)^.id);
Memo1.Lines.Add('name: '+PNoderec(Node.Data)^.name);
Memo1.Lines.Add('pid: '+PNoderec(Node.Data)^.pid);
s := blNode(Node);
ADOQuery2.Close;
ADOQuery2.SQL.Clear;
ADOQuery2.SQL.Text := 'select a.ProductID,a.ProductName,a.ClassID,b.name as ClassName '+
'from t2 a inner join t1 b on b.id=a.ClassID '+
'where a.ClassID in('+s+') or b.parentid in('+s+')' ;
ADOQuery2.Open;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var
node: TTreeNode;
begin
node := TreeView1.Items.GetFirstNode;
while node <> nil do
begin
Dispose(PNoderec(node.Data));
node := node.GetNext;
end;
end;

end.