[TAZ]

For TsComboBox, you can use CB_SETDROPPEDWIDTH to change the combobox dropdown width.

CB_SETDROPPEDWIDTH has no effect on TsComboBoxEx. Is there anything you can use to adjust the TsComboBoxEx dropdown width?

Thanks.

[Support]

Which version of the Delphi do you uses?

I have tried the CB_SETDROPPEDWIDTH message with TsComboBoxEx component, it works well in my test.

[TAZ]

Delphi version is Tokyo 10.2.3

I have attached a project that demonstrates the problem. This is based on https://www.thoughtc…n-width-1058301

Simple and Auto for regular sComboBox works. Does not work for sComboBoxEx.

I also included the last example in the article. It does not work for either.

So, how are you able to get it to work for sComboBoxEx?

Thanks.

'Support' wrote:

Which version of the Delphi do you uses?

I have tried the CB_SETDROPPEDWIDTH message with TsComboBoxEx component, it works well in my test.

[Support]

Thank you for the demo.

Positions of controls are correct there?

Look what I see on my side.

[TAZ]

Well, I feel silly. I will get back to you.

'Support' wrote:

Thank you for the demo.

Positions of controls are correct there?

Look what I see on my side.

[TAZ]

I figured it out and I am not sure why I had to do this. The original problem was that setting the dropdown width was fine when the font size was 8. However, I have the font size set to 12. The dropdown width did not adjust. That was puzzling.

In my research I came across using a TBitmap to set the text length. It worked.

I am not sure why I had to assign the combo box font to the bitmap and then use the bitmap textwidth to get the proper dropdown width. Very odd.

https://stackoverflo…-without-canvas

See attached.

Thanks.

'TAZ' wrote:

Well, I feel silly. I will get back to you.

[TAZ]

One more change to the procedure if the item width is greater than the combo box width. Have to account for the possible vertical scrollbar which was in the wrong place.

I also include changes in the dropdown width if images are included. Interesting adventure.

Code:

procedure ComboBoxEx_AutoWidth(const theComboBox: TsComboBoxEx);
const
HORIZONTAL_PADDING = 4;
var
itemsFullWidth, idx, itemWidth: integer;
c: TBitmap;
begin
c := TBitmap.Create;
try
itemsFullWidth := 0;
c.Canvas.Font.Assign(theComboBox.Font);
for idx := 0 to Pred(theComboBox.Items.Count) do
begin
itemWidth := c.Canvas.TextWidth(theComboBox.Items[idx]);
Inc(itemWidth, (2 * HORIZONTAL_PADDING));
if (itemWidth > itemsFullWidth) then
itemsFullWidth := itemWidth;
end;
if (theComboBox.DropDownCount < theComboBox.Items.Count) then
itemsFullWidth := (itemsFullWidth + GetSystemMetrics(SM_CXVSCROLL));
if (theComboBox.Images nil) then
itemsFullWidth := (itemsFullWidth + theComboBox.Images.Height);
if (itemsFullWidth > theComboBox.Width) then
begin
itemsFullWidth := (itemsFullWidth + (2 * HORIZONTAL_PADDING));
SendMessage(theComboBox.Handle, CB_SETDROPPEDWIDTH, itemsFullWidth, 0);
end;
finally
c.Free;
end;
end;

'TAZ' wrote:

I figured it out and I am not sure why I had to do this. The original problem was that setting the dropdown width was fine when the font size was 8. However, I have the font size set to 12. The dropdown width did not adjust. That was puzzling.

In my research I came across using a TBitmap to set the text length. It worked.

I am not sure why I had to assign the combo box font to the bitmap and then use the bitmap textwidth to get the proper dropdown width. Very odd.

https://stackoverflo…-without-canvas

See attached.

Thanks.

[Support]

Thanks for new demo, I will research it soon.

[Author]

Posts