TadvListBox - scroll by mouse wheel RemoteDesktop

Hi there,
We ve just updated to the latest version. Follow these steps: place e.g. a memo control on a form set TabOrder to 0. Place a TAdvListBox and add 10 items (so that the scrollbar appears).

Start the application. Cursor focus is in the memo (correct). Move the mouse over the TAdvListBox Control and scroll by mouse wheel. As long as you are over the items it will scroll (as expected). If you move out of the control - the wheel does not do anything (as expected).

Now start the application on a RemoteDesktop Session. The wheel scroll function will just work if you click in the listbox. Could you fix this issue please? Our application is running on thin clients. Its excactly the same behaviour.


Attention: We did some further investiagions:

It's NOT RDP! Our customer is using Windows 7. Thats all. Its reproducible not working on Win7.

I have retested this here and I cannot see a behavioral difference between a regular VCL TListBox and TAdvListBox with respect to mouse wheel handling. Internally, TAdvListBox uses a TListBox, so it is normal and expected that the behavior is identical.

Hmhh.. i see. But what could cause this different behaviour on Win10 vs Win7? Have you got a workaround for this?

As explained, the behavior is defined by the LISTBOX class WIndows control that apparently differs between RDP and non RDP. This behavior difference is as such at a level below TAdvListBox and unfortunately, I do not know a workaround for this.

As i said in the second post: its not RDP <> Non RDP. Its just Windows 7. But the same effect. And yes also with the original VCL TListbox. Could you please change the subject to Windows 7 instead of RemoteDesktop? Indeed i found a workaround on Stackoverflow. Maybe it helps some others aswell: http://stackoverflow.com/a/34386680
Thanks for your assistance

Well, regardless of Windows 7 or RDP, it is a behavioral difference of the standard listbox control between Windows 7 / RDP  and Windows 10. Our TAdvListBox is based on the standard VCL TListBox and thus inherits this behavioral difference. As such, if you have a workaround for a standard behavior of TListBox on Windows 7 you do not like, the workaround you apply to it will also work on TAdvListBox.