Delphi lisbox drag and drop

var 
   StartingPoint : TPoint;

implementation

...

procedure TForm1.FormCreate(Sender: TObject) ;
begin
   ListBox1.DragMode := dmAutomatic;
end;

procedure TForm1.ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);
var
  ListBox: TListBox;
  i, TargetIndex: Integer;
  SelectedItems: TStringList;
begin
  Assert(Source=Sender);
  ListBox := Sender as TListBox;
  TargetIndex := ListBox.ItemAtPos(Point(X, Y), False);
  if TargetIndex<>-1 then
  begin
    SelectedItems := TStringList.Create;
    try
      ListBox.Items.BeginUpdate;
      try
        for i := ListBox.Items.Count-1 downto 0 do
        begin
          if ListBox.Selected[i] then
          begin
            SelectedItems.AddObject(ListBox.Items[i], ListBox.Items.Objects[i]);
            ListBox.Items.Delete(i);
            if i<TargetIndex then
              dec(TargetIndex);
          end;
        end;

        for i := SelectedItems.Count-1 downto 0 do
        begin
          ListBox.Items.InsertObject(TargetIndex, SelectedItems[i], SelectedItems.Objects[i]);
          ListBox.Selected[TargetIndex] := True;
          inc(TargetIndex);
        end;
      finally
        ListBox.Items.EndUpdate;
      end;
    finally
      SelectedItems.Free;
    end;
  end;
end;

procedure TForm1.ListBox1DragOver(Sender, Source: TObject; X, Y: Integer; State:  TDragState; var Accept: Boolean) ;
begin
    Accept := Source = ListBox1;
end;

procedure TForm1.ListBox1MouseDown(Sender: TObject; Button: TMouseButton;
   Shift: TShiftState; X, Y: Integer) ;
begin
    StartingPoint.X := X;
    StartingPoint.Y := Y;
end; 

출처 : http://stackoverflow.com/questions/9176684/delphi-listbox-drag-drop-multiple-items