# CellBackgroundPaint in Subclass not working in DarkMode on Windows 11 **URL:** \ **Category:** Windows\ **Created:** [October 17, 2025, 5:22am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737 "2025-10-17T05:22:48Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Sascha\_S](https://forum.xojo.com/user_avatar/forum.xojo.com/sascha_s/32/22328_2.png) [@Sascha\_S](https://forum.xojo.com/u/Sascha_S)\ **Post date:** [October 17, 2025, 5:22am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/1 "2025-10-17T05:22:48Z")
I have a Subclass of DesktopListbox in which i’ve added a PaintCellBackground Event. In this event selected rows will get the Color.Highlight Color as Background Color. This is working as expected while running my app in light mode. **In dark mode the event is executed but the painting does not happen.** If i use the same code in a non-subclassed listbox, it works as expected again. Maybe i’m doing something wrong here? Issue with an example Project: [https://tracker.xojo.com/xojoinc/xojo/-/issues/80042](https://tracker.xojo.com/xojoinc/xojo/-/issues/80042) ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 6:15am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/2 "2025-10-17T06:15:43Z")
I tried three cases: - Default DesktopListbox - Subclassed DesktopListbox with event handler in super class - Subclassed DesktopListbox with event handler in control itself [listboxes.xojo\_binary\_project.zip](https://forum.xojo.com/uploads/short-url/5A3Dglt80IAq9NJzEieCHKDZl3M.zip) (7.3 KB) All three work ![image](https://forum.xojo.com/uploads/default/original/3X/e/6/e646e28e6f6d553e75e918db4aceef3981e1aa60.jpeg) ---
**Author:** ![Sascha\_S](https://forum.xojo.com/user_avatar/forum.xojo.com/sascha_s/32/22328_2.png) [@Sascha\_S](https://forum.xojo.com/u/Sascha_S)\ **Post date:** [October 17, 2025, 6:16am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/3 "2025-10-17T06:16:49Z")
And my example also works? ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 6:17am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/4 "2025-10-17T06:17:55Z")
![image](https://forum.xojo.com/uploads/default/original/3X/7/1/717fd73c4319d194b74aa69ef335bf6f7e1d74f9.jpeg) ---
**Author:** ![Sascha\_S](https://forum.xojo.com/user_avatar/forum.xojo.com/sascha_s/32/22328_2.png) [@Sascha\_S](https://forum.xojo.com/u/Sascha_S)\ **Post date:** [October 17, 2025, 6:19am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/5 "2025-10-17T06:19:58Z")
Both listboxes should show selected entries with a blue (highlight color) background. Your image shows the issue i encounter. ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 6:23am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/6 "2025-10-17T06:23:33Z")
The left one is only blue if it has the focus ![image](https://forum.xojo.com/uploads/default/original/3X/a/1/a193ffbd5abad2be2b390478ea5f6580c3e61865.jpeg) ---
**Author:** ![Sascha\_S](https://forum.xojo.com/user_avatar/forum.xojo.com/sascha_s/32/22328_2.png) [@Sascha\_S](https://forum.xojo.com/u/Sascha_S)\ **Post date:** [October 17, 2025, 6:24am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/7 "2025-10-17T06:24:22Z")
Exactly. It behaves different from the right one, but it shouldn’t. 🙂 ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 6:25am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/8 "2025-10-17T06:25:49Z")
Ah, now I understand. The left one is the wrong one 😄 . Yeah, reproducable on my side. ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 6:27am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/9 "2025-10-17T06:27:44Z")
Oh no, it isn’t. You use `Return RaiseEvent PaintCellBackground( g, row, column )` As you don’t return anything in the control in the window the painting is handled by Xojo and not by your code. ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 6:28am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/10 "2025-10-17T06:28:12Z")
Return True and it works ![image](https://forum.xojo.com/uploads/default/original/3X/5/c/5cc80986c497c00ff4e2426f473ce06faca85434.jpeg) ![image](https://forum.xojo.com/uploads/default/original/3X/5/6/56a9fcb041b081e72a497f5d682177190024f7a0.jpeg) ---
**Author:** ![Sascha\_S](https://forum.xojo.com/user_avatar/forum.xojo.com/sascha_s/32/22328_2.png) [@Sascha\_S](https://forum.xojo.com/u/Sascha_S)\ **Post date:** [October 17, 2025, 6:57am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/11 "2025-10-17T06:57:29Z")
Thank you @StefanA, i see the problem here now. 🙂 How can i make sure the Code in the Subclassed DesktopListbox is respected without me having to add a PaintCellBackground Event in each of my object which use this subclass? Because i need the `Return RaiseEvent PaintCellBackground( g, row, column )` for instances in which i use this subclass but extended it’s functionality in the PaintCellBackground Event and i don’t want to add a `Return True` i all those instances. And sometimes i need to `Return False` here, too. ---
**Author:** ![StefanA](https://forum.xojo.com/user_avatar/forum.xojo.com/stefana/32/286_2.png) [@StefanA](https://forum.xojo.com/u/StefanA)\ **Post date:** [October 17, 2025, 7:17am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/12 "2025-10-17T07:17:43Z")
Well, if you want to handle it yourself you have to return true. Otherwise Xojo will handle it. We use this for such cases: ```auto If Not RaiseEvent PaintCellBackground( g, row, column ) Then Return True End If ``` So you have the chance to handle it in the control itself. Otherwise the super class will handle it. ---
**Author:** ![Sascha\_S](https://forum.xojo.com/user_avatar/forum.xojo.com/sascha_s/32/22328_2.png) [@Sascha\_S](https://forum.xojo.com/u/Sascha_S)\ **Post date:** [October 17, 2025, 7:38am UTC](https://forum.xojo.com/t/cellbackgroundpaint-in-subclass-not-working-in-darkmode-on-windows-11/86737/13 "2025-10-17T07:38:36Z")
Thanks, Stefan. I now understand what the problem is and what I need to do. And I’m glad it’s not a bug. I’ll close my case in the issue tracker. Have a nice weekend! 🙂