hsr/////////////////////////////////////////////////
재귀호출은 최용일님것 사용하구요
Treeview1,Treeview2의 속성중 DragMode는 dmAutomatic으로한후

procedure TForm1.TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);
var
   Item : TTreeNode;
   CursorPos: TPoint;
begin
   if (Sender is TTreeView) and (Source is TTreeView) then begin
      if (TTreeView(Source).Selected <> nil)//and(TTreeView(Sender).DropTarget <> nil)
          and(TTreeView(Source).Selected <> TTreeView(Sender).DropTarget) then begin

         CursorPos := TTreeView(Sender).ScreenToClient(Point(X,Y));
         Item := TTreeView(Sender).GetNodeAt(X, Y);

         //이동할 서브 노드 리스트(서로다른 트리뷰일때 MoveTo로할경우 문제생김)
         //Item := TTreeView(Sender).Items.AddChild(TTreeView(Sender).DropTarget, '');
         Item := TTreeView(Sender).Items.AddChild(Item, '');
         Item.Assign(TTreeView(Source).Selected);

         CopyChildNode(TTreeView(Source), TTreeView(Sender), TTreeView(Source).Selected, Item);

         TTreeView(Source).Items.Delete(TTreeView(Source).Selected);
      end;
   end;
end;
//최용일님의 재귀호출 사용
procedure TForm1.CopyChildNode(SourceTreeView, DestTreeView: TTreeView; Source, Dest: TTreeNode);
var
    Index: Integer;
    Item: TTreeNode;
begin
    for Index := 0 to Source.Count - 1 do
    begin
        // Copies Node
        Item := DestTreeView.Items.AddChild(Dest, '');
        Item.Assign(Source[Index]);
        // Copy Child Nodes
        if Source.Item[Index].HasChildren then
            CopyChildNode(SourceTreeView, DestTreeView, Source[Index], Item);
    end;

    // Deletes Node
   //for Index := Source.Count - 1 to 0 do
   //   SourceTreeView.Items.Delete(Source[Index]);
   if  Source.Count > 0 then
        SourceTreeView.Items.Delete(Source[0]);
end;

procedure TForm1.TreeView1DragOver(Sender, Source: TObject; X, Y: Integer;
  State: TDragState; var Accept: Boolean);
begin
    Accept := (Sender is TTreeView) and (Source is TTreeView)
              //and(TTreeView(Source).Selected <> nil)and(TTreeView(Sender).DropTarget <> nil);
end;