[Bug] [Android] ToolkitPlatform.Context used by AvatarView is causing a NullReferenceException

[Cfun1]

Description

AvatarView causing a System.NullReferenceException at this line

XamarinCommunityToolkit/src/CommunityToolkit/Xamarin.CommunityToolkit/Views/AvatarView/ImageSourceValidator.android.ios.macos.uwp.wpf.gtk.tizen.cs

Line 43 in 7db4941

var imageSource = await handler.LoadImageAsync(source, ToolkitPlatform.Context).ConfigureAwait(false);

because of ToolkitPlatform.Context

XamarinCommunityToolkit/src/CommunityToolkit/Xamarin.CommunityToolkit/Startup/ToolkitPlatform.android.cs

Line 21 in aba6205

return renderer.View.Context ?? throw new NullReferenceException($"{nameof(Context)} cannot be null");

Steps to Reproduce

1. Run the app, click on physical back button.

Expected Behavior

No exception should be thrown.

Actual Behavior

Exception thrown: System.NullReferenceException: 'Object reference not set to an instance of an object.'

Basic Information

• Version with issue: 1.2.0-pre2
• Last known good version: -
• Platform Target Frameworks: Tested on Android only.
  • iOS:
  • Android 10:
  • UWP:
• Affected Devices: Emulator and real devices.

Reproduction Link

https://github.com/Cfun1/XamsungHealth

cc @pictos

[AndreiMisiukevich]

Hmmm, should we do lazy loading of context (store context after first request)

[pictos]

@AndreiMisiukevich Yes, I believe that will be the best approach, I already did a fix for it, but need to find it again on my branches ocean.

More info for others that want to know more about it:

In this case, the issue is because when you press the back button, the app goes to background and when the avatarView tries to access the Context that's null because there's no MainPage, but the context keeps the same (because the way how Forms works)

[AndreiMisiukevich]

@pictos please submit a PR once you have a time)