Bug 46526 - On UWP, the expected application lifecycle events for suspend and resume are not fired
Summary: On UWP, the expected application lifecycle events for suspend and resume are ...
Status: RESOLVED INVALID
Alias: None
Product: Forms
Classification: Xamarin
Component: Windows ()
Version: 2.3.2
Hardware: PC Windows
: --- normal
Target Milestone: ---
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2016-11-06 00:45 UTC by John Hardman
Modified: 2016-11-13 18:09 UTC (History)
3 users (show)

Tags: Application lifecycle OnSleep OnResume UWP
Is this bug a regression?: ---
Last known good build:

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Status:
RESOLVED INVALID

Description John Hardman 2016-11-06 00:45:29 UTC
On UWP (tested on both phone and desktop), the OnSleep and OnResume methods described in the XF documentation at the following URL, are not executed:
https://developer.xamarin.com/guides/xamarin-forms/working-with/app-lifecycle/

Another dev has reported the same thing on the forums at:
https://forums.xamarin.com/discussion/81877/onresume-onsleep-do-not-fire-on-uwp

Ideally, those methods should get called. But, if they are not going to be called, the documentation should be updated to match the actual behavior.

For info, there is some useful information about lifecycle on Windows 10 at the following address:
https://msdn.microsoft.com/en-gb/windows/uwp/launch-resume/app-lifecycle
Comment 1 John Hardman 2016-11-06 00:53:30 UTC
As per the thread mentioned above, there only seems to be one scenario when OnSleep is called on UWP, described by the author of the forum post as follows:
"The only time the onsleep fires is when i hold the back button and terminate the app using the X"
Comment 2 Paul DiPietro [MSFT] 2016-11-07 17:38:51 UTC
From that MSDN page:

"A note about debugging using Visual Studio: Visual Studio prevents Windows from suspending an app that is attached to the debugger. This is to allow the user to view the Visual Studio debug UI while the app is running. When you're debugging an app, you can send it a suspend event using Visual Studio. Make sure the Debug Location toolbar is being shown, then click the Suspend icon."

The events fire internally on one of our control gallery projects when using the aforementioned toolbar, so I'd be led to believe that this is the cause. I presume OnSleep firing due to app termination would be due to the debugger no longer running.
Comment 3 John Hardman 2016-11-13 18:09:22 UTC
@Paul DiPietro - Yes, you are correct. Please excuse my brain fade :-)

Setting to Resolved/Invalid