[Bug] Android - OnDisappearing gets invoked when the app/page disappears due to external events.

[wfahnestock]

Description

Documentation on OnDisappearing states that this shouldn't be the case, so I'm not sure if the documentation is wrong or if this is genuinely a bug.

Steps to Reproduce

1. Override OnDisappearing on a Page
2. Press the home button or navigate away from the Xamarin.Forms App

Expected Behavior

Documentation states "OnDisappearing() is called when the page disappears due to navigating away from the page within the app. It is not called when the app disappears due to an event external to the app (e.g. user navigates to the home screen or another app, a phone call is received, the device is locked, the device is turned off)."

Actual Behavior

OnDisappearing is actually called when an external event described above happens. I can confirm it gets called when the device receives a phone call as well.

Basic Information

• Version with issue: Tested on 5.0.0.2012 and 5.0.0.2337
• Last known good version: Unknown
• Platform Target Frameworks:
  • Android: R 11.0 - API 30 & Android 10 - API 29
• NuGet Packages: .NETStandard, Xamarin.Essentials, Xamarin.Forms
• Affected Devices: Android Emulator (Pixel 3a R 11.0 - API 30), LG V35 ThinQ (Android 10 - API 29)

Environment

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Microsoft Visual Studio Community 2019
Version 16.11.8
VisualStudio.16.Release/16.11.8+32002.261
Microsoft .NET Framework
Version 4.8.04084

Installed Version: Community

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Xamarin.Android SDK   12.0.0.3 (d16-11/f0e3c2d)
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Xamarin.iOS and Xamarin.Mac SDK   15.2.0.17 (738fde344)
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[jfversluis]

Thanks for the report! Do you see this only on Android? Did you also test iOS or UWP?

[wfahnestock]

Thanks for the report! Do you see this only on Android? Did you also test iOS or UWP?

Only seeing this on Android at the moment. My dev environment for iOS is currently tied up on another project, so unfortunately I cannot test on iOS on this time. I am also not developing this application for UWP so I haven't tested that either, so far it is only Android that I've noticed this happening on.

[petes05]

I experienced this issue as well. OnAppearing/OnDisappearing would be called when the device's screen was turned on/off.

I got around it by setting SendAppearingEventOnResume and SendDisappearingEventOnPause to false. https://docs.microsoft.com/en-us/xamarin/xamarin-forms/platform/android/page-lifecycle-events