[HeDiBo]

The standard TDBLookupComboBox does not react to the mouse wheel in its dropdown list. However this could very easily be implemented:

    procedure TsDBLookupComboBox.MouseWheelHandler(var Message: TMessage);
    var
      i: Integer;
    begin
      if ListVisible then
      begin
        for i := 0 to Mouse.WheelScrollLines - 1 do
          if Message.WParam < 0 then
            FDataList.Perform(WM_KEYDOWN, VK_DOWN, 0)
          else
            FDataList.Perform(WM_KEYDOWN, VK_UP, 0);
      end
      else
        inherited MouseWheelHandler(Message);
    end;

Would you be willing to implement this?

[HeDiBo]

My code is only applicable to TDBLookupComboBox. For TsDBLookupComboBox the ListSW scrolling window should be used in a similar way.

[Support]

Thanks for code, I will try it soon.

[HeDiBo]

Will it still come in a next release?

[Support]

I have checked your solution and it did not help in my test.
Data may be scrolled inside the ComboBox, but not in the popup window.
You tried this solution?

[Stephane Senecal]

My 2 cent here, I think the mouse wheel should only work when the combobox’s list is dropped down, but not when the combobox’s list is closed even though it is Windows’s default behavior.
We had many many problems with customers changing values without noticing by scrolling focused comboboxes (focus doesn’t mean under mouse cursor).

Stephane Senecal
CIS Group
Delphi programmer since 2001

[HeDiBo]

Yes Stephane. I completely agree.

[Support]

This behavior will be changed in the v15.10

[HeDiBo]

It works now as expected 💎
Please close this topic.

[Author]

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