Application.Exit() doesn't work if app doesn't have any windows open

Describe the bug While trying to implement single instance redirection, I noticed that the Exit() API doesn’t work unless the app has windows open. In the case of redirecting activation, after redirecting the activation, the second instance needs to be closed (without ever showing any windows). But calling Exit() doesn’t do anything, the process stays running…

Steps to reproduce the bug

Steps to reproduce the behavior:

1. Create a new WinUI 3 Desktop app, and in OnLaunched, update it to the following (exits itself after 6 seconds and never shows window)…

1. Launch the app
2. Open Task Manager, and notice that the process is still running (under background processes) after 6 seconds and never exits

Expected behavior App should exit. The Exit() API works if there’s an open activated window when it’s called, but doesn’t work when there’s no open window.

Version Info

NuGet package version: [WinUI 3 - Windows App SDK 1.0.0-preview1

Windows app type:

UWP	Win32
	Yes

Windows version	Saw the problem?
Insider Build (xxxxx)	Yes
May 2021 Update (19043)
October 2020 Update (19042)
May 2020 Update (19041)
November 2019 Update (18363)
May 2019 Update (18362)
October 2018 Update (17763)
April 2018 Update (17134)
Fall Creators Update (16299)
Creators Update (15063)

Device form factor	Saw the problem?
Desktop	Yes
Xbox
Surface Hub
IoT

Additional context

Workaround is to use Process.GetCurrentProcess().Kill().

[pratikone]

thanks @DJRM2021 . i double checked. My fix did make it in stable 1.3 release. 🎉🎉 (it wasn’t in experimental release but I suppose they picked up more commits later for stable branch and this is how it got in ). I have correctly added the milestone and will close the bug.

[pratikone]

Thanks for posting this error. I found the problem and fixed it internally. Should come up in some future release. This bug will close automatically with that.