Enhancement Allow unload AssemblyLoadContext which contains Avalonia content #13935

[MakesYT]

What does the pull request do?

Allows AssemblyLoadContext that contains Avalonia content to be unloaded

What is the current behavior?

Allowed AssemblyLoadContext that contains Avalonia content to be unloaded
Allowed you to uninstall Avalonia property registration on a specific type
Allowed to delete the IAssemblyDescriptorResolver StandardAssetLoader _assemblyNameCache

What is the updated/expected behavior with this PR?

Usage
Add the following methods to the AssemblyLoadContext Unloading event

Unloading += (sender) =>
        {
            AvaloniaPropertyRegistry.Instance.UnregisterByModule(sender.Assemblies.First().DefinedTypes);
            Application.Current.Styles.Remove(MainWindow.Style);//You need to manually remove all style references from AssemblyLoadContext
            MainWindow.Style= null;
            AssetLoader.InvalidateAssemblyCache(sender.Assemblies.First().GetName().Name);
           
        };

How was the solution implemented (if it's not obvious)?

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

None

Obsoletions / Deprecations

Added the RemoveAssembly method in IAssetLoader

 /// <summary>
        /// Removes the assembly from the cache.
        /// </summary>
        /// <param name="name">The Assemblies.First().GetName().Name</param>
        void InvalidateAssemblyCache(string name);
        /// <summary>
        /// Removes all assemblies from the cache.
        /// </summary>
        void InvalidateAssemblyCache();

@grokys @kekekeks & @danwalmsley

Fixed issues

[MakesYT]

@dotnet-policy-service agree

[avaloniaui-bot]

You can test this PR using the following package version. 11.1.999-cibuild0043008-beta. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[timunie]

@MakesYT you may want to work on top of #13970 as this may change some important steps. Just an idea, haven't checked it on my own deep enough

[MakesYT]

Usage
Add the following methods to the AssemblyLoadContext Unloading event

Unloading += (sender) =>
{
     AvaloniaPropertyRegistry.Instance.UnregisterByModule(sender.Assemblies.First().DefinedTypes);
};

[avaloniaui-bot]

You can test this PR using the following package version. 11.1.999-cibuild0043140-beta. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.1.999-cibuild0043347-beta. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.1.999-cibuild0044424-beta. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[maxkatz6]

cc @kekekeks

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0046354-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0046361-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0046378-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[maxkatz6]

@MakesYT since IAssetsLoader is a public API, and it's not possible to add interface method to a public API without breaking ABI, these changes are considered a breaking change. But it should be a pretty minor one, that we can accept. Can you run nuke ValidateApiDiff command in the repository root? It will update api-diff related files, which you then can commit in this PR. So CI builds can be green again.

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0046969-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[MakesYT]

@maxkatz6 now it's ok