Hi all,

I have an Array of dynamically created LookupCombos. The LookupDataset
of each LookupCombo depends on the current record of the previous
LookupCombo.

I want to display the Combos next to each other. To avoid unnecessary
space between the Combos I need to calculate the Width (in Pixels) of
the Text displayed in the Combos.

I tried somtheing like this:

var
FComboCanvas: TControlCanvas;
sText: String;
tw: Integer;
begin
FComboCanvas := TControlCanvas.Create;
try
FComboCanvas.Control := FLCNode {the ComboBox};
sText := FQryLkNode.FieldByName( 'TN_TEXT' ).AsString;
tw := FComboCanvas.TextWidth( sText ) + 4;
FLCNode.Width := Max( 20, tw );
finally
FComboCanvas.Free;
end;
end;

But this gives me the wrong result. Does anyone know how to get
the exact width ?

My second problem is to find an event when to adjust the width.
I tried ComboBox.OnCloseUp but when this event occurs then
sometimes

FQryLkNode.FieldByName('TNR_ID_NODEREL').IsNull = true;

I guess that during this event the Dataset is scrolling and therefor
has no current record. "AfterScroll" fires too often.
Is there a better event for this ?

Note: The Lookup-Datasets of the Combos have no KeySources because
I need to write the selected record-keys manually into a table because
the structure of the Data is TreeView-like.

Many TIA,
Markus