用treeview表示层次结构

Question

如何用treeview显示出层次结构，数据在数据库中
表：部门结构
部门ID      部门名       上级部门
1           A                 
2           B             A
3           C             A
4           D             B
5           E             B
......A为顶层部门，B和C是A的下属部门,D和E是B的下属部门......
将这个关系用treeview表示，要怎么写?

Answer 1

1）按部门名遍历记录，建立其顶级接点Node
2）遍历“上级部门”是该部门的记录，建立Node的子节点

Answer 2

能给出点代码吗？
我刚接触delphi不久，对许多控件不是很熟悉

Answer 3

Function  TFrm_qcsp.AddNode(TreeView:TTreeview;Node:TTreeNode;ADOQ:TADOQuery):TTreeNode;
var
  Node1:TTreeNode;
  s:PString;
begin
  Node1:=TreeView.Items.AddChild(Node,ADOQ.FieldByName('flmc').Text);
  New(s);
  s^:=ADOQ.FieldByName('id').Text;
  Node1.Data:=s;
  Result:=Node1;
end;Function  TFrm_qcsp.SearchNode(TreeView:TTreeView;Txts:String):TTreeNode;
var
  i:integer;
  s:PString;
begin
  Result:=nil;
  For i:=0 To TreeView.Items.Count-1 Do
    begin
      s:=TreeView.Items[i].Data;
      If s^=Txts Then
        begin
          Result:=TreeView.Items[i];
          Exit;
        end;
    end;
end;
procedure TFrm_qcsp.formshow(Sender: TObject);
var
  i,Rec_Num:integer;
  Node1,Node2:TTreeNode;
  var s_sql1,s_sql2:string;
begin
  TreeView1.Items.Clear;
  TreeView1.Items.BeginUpdate;
  Node1:=TreeView1.Items.GetFirstNode;
  with adoquery4 do
    begin
      close;
      sql.Clear;
      sql.Add('select * from tba_flbm order by id');
      open;
    end;
  If ADOquery4.RecordCount>0 Then
  Begin
    Rec_Num:= ADOQuery4.RecordCount;
    For i:=0 To Rec_Num-1 Do
    begin
      If ADOQuery4.FieldByName('parent').Text='0' Then
        Node2:=AddNode(TreeView1,Node1,ADOQuery4)
      Else
        begin
          Node2:=SearchNode(TreeView1,ADOQuery4.FieldByName('parent').Text);
          If Node2<>nil Then
            AddNode(TreeView1,Node2,ADOQuery4);
        end;
        ADOQuery4.Next;
      end;
   End;
   TreeView1.Items.EndUpdate;
   If ADOquery4.RecordCount>0 Then
    self.TreeView1.Items[0].Expanded:=true;
---------

Answer 4

建议:先选出"上级部门"为空的,即最顶级的记录,添加到treeview,然后在treeview的onexpanding事件中每展开一个节点时,读取属于该节点的下级记录并添加到treeview,依次类推