Proposal: WinUI Win32 apps should use dark titlebar when app is in dark mode

Proposal: WinUI Win32 apps should support dark title bar

Summary

A few versions back, File Explorer got a dark mode makeover, including a dark titlebar. WinUI Win32 apps use the standard white title bar regardless of whether the rest of the app is dark or not. WinUI Win32 apps should use the same API to make themselves have a dark title bar when the main content is in dark mode.

Rationale

• The dark mode title bar API already exists in Windows, and users are used to it thanks to File Explorer
• UWP XAML apps do not suffer from this visual clash
• It looks bad to have a white title bar with black content

Scope

Capability	Priority
The titlebar should obey the system theme by becoming dark in dark mode unless the RequestedTheme property is overridden in App.xaml or maybe MainWindow.xaml	Must
Provide an API on the Window class to control the title bar dark mode setting—not sure how useful this would be	Could

Mockups

With titlebar accent color enabled in personalization settings	Titlebar color settings disabled

Open Questions

It is not clear to me how it would determine whether to use light or dark mode title bar if the app’s theme were overridden. It doesn’t look like the Window class has a RequestedTheme property (but it probably should, like Page?), so it might have to depend only on the app-level setting.

I know a lot of others are interested in greater titlebar customization like in UWP, but I think this is a good place to start for the titlebar.

[BreeceW]

Maybe WinUI 3 should generally use a more modern title bar like in UWP apps

Agreed—thing is, having the normal Win32 title bar dark mode-aware would be a nice stopgap without having to make any new APIs in WinUI until a better title bar could be made. If there were going to be a “modernized” title bar, I would hope it would be exactly identical to the UWP title bar—not a crude imitation like in Windows Terminal.

[Austin-Lamb]

We have implemented this internally and it will be in the next preview release. We’ll also have support for customizing the title bar more (like you could in UWP) for WinUI 3 Desktop apps, so stay tuned for much better title bars.