[Lazarus] Listboxes disappear after form resize

[Frans]

Hi.

I have a strange problem with a sizeable form. The form has 2 listboxes that are anchored to the 
groupbox (leftlistbox and rightlistbox) and a speedbutton in between (rightlistbox). The form is 
resizeable and that is no problem, until I try to change the number of columns in the listbox, 
depending on the width of the form after resizing. The zip file contains 3 pictures, the form at 
starting point, the form after the first resize, both listboxes are gone, and the form after another 
resize, the listboxes are back again. The formules I use  are:

procedure TPlayerForm.FormResize(Sender: TObject);
begin
   leftlistbox.Width := leftlistbox.Constraints.MinWidth + (Self.Width - Self.Constraints.MinWidth) 
div 2;
// the rightlistbox changes through the anchors
end;

procedure TPlayerForm.ListBoxResize(Sender: TObject);
begin
   leftlistbox.Columns := lftlistbox.Width div leftlistbox.Constraints.MinWidth;
   rightlistbox.Columns := leftlistbox.Columns;
end;

-- 
mvg
Frans van Leeuwen
M 06-51695390

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