Author: Tomas Rutkauskas

I have a treeview which I need to be able to drag items from onto a listbox (they 
have to be deleted from the treeview when moved, of course). I have been able to do 
this between two listboxes, but this one eludes me. Can anyone get me started 
please?

Answer:
1   
2   procedure TForm1.TreeView1MouseDown(Sender: TObject; Button:
3     TMouseButton; Shift: TShiftState; X, Y: Integer);
4   begin
5     if TreeView1.Items.Count = 0 then
6       exit;
7     if Button = mbLeft then
8       TreeView1.BeginDrag(False); {begin drag}
9   end;
10  
11  procedure TForm1.ListBox1DragOver(Sender, Source: TObject; X, Y:
12    Integer; State: TDragState; var Accept: Boolean);
13  begin
14    Accept := (Sender = TreeView1);
15  end;
16  
17  procedure TForm1.ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);
18  var
19    dx: integer;
20    Node: TTreeNode;
21  begin
22    if Source = TreeView1 then
23    begin
24      Node := TreeView1.Selected;
25      if Node <> nil then
26      begin
27        with TListBox(Sender) do
28        begin
29          dx := ItemAtPos(Point(X, Y), false);
30          Items.Insert(dx, Node.Text);
31          {or use:
32          Items.InsertObject(dx, Node.Text, Pointer(Node.Data)); }
33        end;
34        Node.Delete;
35      end;
36    end;
37  end;