Speech Recognition Windows Ensure unsubscribe from events on Stop Recording

[VladislavAntonyuk]

Speech Recognition Windows Ensure unsubscribe from events on Stop Recording

[Copilot]

Pull Request Overview

This PR ensures that speech recognizers on Windows clean up event subscriptions and are disposed when stopping recording. It also updates offline recognizer startup logic, adds disposal to the sample view model, and declares the microphone capability in the sample app manifest.

• Unsubscribe from events and dispose recognizers in StopRecording/InternalStopListening finally blocks.
• Only start recognition when the recognizer is idle (online) or stopped (offline).
• Make the sample view model disposable and add microphone capability to the manifest.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/SpeechToTextImplementation.windows.cs	Move event unsubscriptions and disposal into StopRecording finally block; guard start on idle state.
src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/OfflineSpeechToTextImplementation.windows.cs	Mirror cleanup in InternalStopListening, switch to LoadGrammarAsync, and guard RecognizeAsync on stopped state.
samples/CommunityToolkit.Maui.Sample/ViewModels/Essentials/SpeechToTextViewModel.cs	Implement IAsyncDisposable for speech-to-text cleanup; simplify default locale selection.
samples/CommunityToolkit.Maui.Sample/Platforms/Windows/Package.appxmanifest	Add <DeviceCapability Name="microphone"/> under <Capabilities>.

Comments suppressed due to low confidence (3)

src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/SpeechToTextImplementation.windows.cs:108

• Consider adding unit tests to verify that event handlers are properly removed and that the recognizer is disposed after StopRecording to prevent memory leaks.

speechRecognizer?.Dispose();

src/CommunityToolkit.Maui.Core/Essentials/SpeechToText/OfflineSpeechToTextImplementation.windows.cs:113

• Switching from synchronous LoadGrammar to LoadGrammarAsync without awaiting the load can lead to recognition starting before the grammar is ready. Consider awaiting completion (e.g., handle the GrammarLoadCompleted event) before calling RecognizeAsync.

offlineSpeechRecognizer.LoadGrammarAsync(new DictationGrammar());

samples/CommunityToolkit.Maui.Sample/ViewModels/Essentials/SpeechToTextViewModel.cs:56

• Removing the platform-specific default-language fallback changes the initial locale selection behavior. If intentional, add a comment; otherwise restore the previous logic or provide a configurable fallback.

CurrentLocale = Locales.FirstOrDefault();

[TheCodeTraveler]

Thanks Vlad! I see you've added a few items to the sample app, like <DeviceCapability Name="microphone"/> and IAsyncDisposable.

Could you also open a Docs PR to include these before we merge this PR?

[VladislavAntonyuk]

@TheCodeTraveler, it is already in the docs:

[TheCodeTraveler]

Nice! Could you also add a section that recommends using IDisposable or IAsyncDisposable?

[VladislavAntonyuk]

I don't think it's recommend. For example users may register their service as Singleton.