Expand and Collaps TreeNodes

lawefa

Hello everyone

I would like to close the other open nodes in the same level in an ElXTree tree when expanding a node.

How can I implement this? 

I can't find any information about the OnItemExpand or OnItemExpanding events in the HelpFiles or MegaDemos

Best regards gerd

Eugene Balabuev (LMD)

There are no special built-in utility for that, so you just have to iterate items and collapse all siblinks manually. Use OnItemExpand event for that:

procedure TForm20.ElXTree1ItemExpand(Sender: TObject; Item: TElXTreeItem);

begin

  ElXTree1.Items.BeginUpdate;

  try

    var itm := Item.GetFirstSibling;

    while itm <> nil do

    begin

      if itm <> Item then

        itm.Collapse(True);

      itm := itm.GetNextSibling;

    end;

  finally

    ElXTree1.Items.EndUpdate;

  end

end;