Fix warnings, code styling, etc.

samples/Plugin.Maui.Audio.Sample/ViewModels/AudioRecorderPageViewModel.cs

@@ -111,7 +111,7 @@ public int SelectedSampleRate
 
 	async void PlayAudio()
 	{
-		if (audioSource != null)
+		if (audioSource is not null)
 		{
 			audioPlayer = this.audioManager.CreateAsyncPlayer(((FileAudioSource)audioSource).GetAudioStream());
 

samples/Plugin.Maui.Audio.Sample/ViewModels/MusicPlayerPageViewModel.cs

@@ -130,7 +130,7 @@ public double Volume
 		get => audioPlayer?.Volume ?? 1;
 		set
 		{
-			if (audioPlayer != null)
+			if (audioPlayer is not null)
 			{
 				audioPlayer.Volume = value;
 			}
@@ -142,7 +142,7 @@ public double Balance
 		get => audioPlayer?.Balance ?? 0;
 		set
 		{
-			if (audioPlayer != null)
+			if (audioPlayer is not null)
 			{
 				audioPlayer.Balance = value;
 			}

src/Plugin.Maui.Audio/AudioMixer/AudioMixer.cs

@@ -45,11 +45,15 @@ public class AudioMixer : IDisposable
 	/// <param name="numberOfChannels">The number of audio channels to manage.</param>
 	public AudioMixer(IAudioManager audioManager, int numberOfChannels)
 	{
-		if (audioManager == null)
+		if (audioManager is null)
+		{
 			throw new ArgumentNullException(nameof(audioManager));
+		}
 
 		if (numberOfChannels <= 0)
+		{
 			throw new ArgumentOutOfRangeException(nameof(numberOfChannels), "Number of channels must be positive.");
+		}
 
 		this.audioManager = audioManager;
 		ChannelCount = numberOfChannels;
@@ -94,8 +98,10 @@ public void Play(int channelIndex, bool loop = false)
 	public void Play(int channelIndex, IAudioSource audioClip, bool loop = false)
 	{
 		ValidateChannelIndex(channelIndex);
-		if (audioClip == null)
+		if (audioClip is null)
+		{
 			throw new ArgumentNullException(nameof(audioClip));
+		}
 
 		var player = channels[channelIndex];
 		player.Stop(); 
@@ -177,8 +183,10 @@ public void PlayAll()
 	public void SetSource(int channelIndex, IAudioSource audioClip)
 	{
 		ValidateChannelIndex(channelIndex);
-		if (audioClip == null)
+		if (audioClip is null)
+		{
 			throw new ArgumentNullException(nameof(audioClip));
+		}
 
 		var player = channels[channelIndex];
 		player.Stop(); 
@@ -244,7 +252,9 @@ public void SetVolume(int channelIndex, float volume)
 	void ValidateChannelIndex(int channelIndex)
 	{
 		if (channelIndex < 0 || channelIndex >= ChannelCount)
+		{
 			throw new ArgumentOutOfRangeException(nameof(channelIndex), $"Channel index must be between 0 and {ChannelCount - 1}.");
+		}
 	}
 
 	/// <summary>
@@ -307,7 +317,9 @@ public float GetDistanceDecay(float dist)
 	protected virtual void Dispose(bool disposing)
 	{
 		if (IsDisposed)
+		{
 			return;
+		}
 
 		foreach (var player in channels)
 		{

src/Plugin.Maui.Audio/AudioPlayer/AudioPlayer.android.cs

@@ -142,12 +142,12 @@ public bool Loop
 
 	void PrepareAudioSource()
 	{
-		if (audioBytes == null && string.IsNullOrWhiteSpace(file))
+		if (audioBytes is null && string.IsNullOrWhiteSpace(file))
 		{
 			throw new ArgumentException("audio source is not set");
 		}
 
-		if (audioBytes != null && OperatingSystem.IsAndroidVersionAtLeast(23))
+		if (audioBytes is not null && OperatingSystem.IsAndroidVersionAtLeast(23))
 		{
 			stream = new MemoryStream(audioBytes);
 			var mediaSource = new StreamMediaDataSource(stream);
@@ -172,6 +172,11 @@ void PrepareAudioSource()
 		}
 		else
 		{
+			if (file is null)
+			{
+				throw new FailedToLoadAudioException("Provided file was null");
+			}
+
 			AssetFileDescriptor afd = Android.App.Application.Context.Assets?.OpenFd(file)
 				?? throw new FailedToLoadAudioException("Unable to create AssetFileDescriptor.");
 

src/Plugin.Maui.Audio/AudioPlayer/AudioPlayer.macios.cs

@@ -104,7 +104,7 @@ public bool Loop
 
 	internal AudioPlayer(AudioPlayerOptions audioPlayerOptions)
 	{
-		if (emptySource == null)
+		if (emptySource is null)
 		{
 			byte[] empty = new byte[16];
 			int sampleRate = 44100;
@@ -127,7 +127,7 @@ internal AudioPlayer(AudioPlayerOptions audioPlayerOptions)
 	/// <exception cref="FailedToLoadAudioException">Thrown when the audio stream cannot be loaded.</exception>
 	public void SetSource(Stream audioStream)
 	{
-		if (player != null)
+		if (player is not null)
 		{
 			player.FinishedPlaying -= OnPlayerFinishedPlaying;
 			player.DecoderError -= OnPlayerError;

src/Plugin.Maui.Audio/AudioRecorder/AudioRecorder.android.cs

@@ -39,7 +39,7 @@ public AudioRecorder(AudioRecorderOptions options)
 		var packageManager = Android.App.Application.Context.PackageManager;
 
 		CanRecordAudio = packageManager?.HasSystemFeature(Android.Content.PM.PackageManager.FeatureMicrophone) ?? false;
-		this.audioRecorderOptions = options;
+		audioRecorderOptions = options;
 	}
 
 	public Task StartAsync(AudioRecorderOptions? options = null) => StartAsync(GetTempFilePath(), options);
@@ -57,17 +57,17 @@ public Task StartAsync(string filePath, AudioRecorderOptions? recordingOptions =
 
 		if (recordingOptions is not null)
 		{
-			this.audioRecorderOptions = recordingOptions;
+			audioRecorderOptions = recordingOptions;
 		}
 
 		audioFilePath = filePath;
 
 		// solve some parameters needed for AudioRecord/MediaRecorder
 		ChannelIn channelIn =
 			SharedChannelTypesToAndroidChannelTypes(audioRecorderOptions.Channels, audioRecorderOptions.ThrowIfNotSupported);
-		this.sampleRate = audioRecorderOptions.SampleRate;
-		this.bitDepth = (int)audioRecorderOptions.BitDepth;
-		this.channels = channelIn == ChannelIn.Mono ? 1 : 2;
+		sampleRate = audioRecorderOptions.SampleRate;
+		bitDepth = (int)audioRecorderOptions.BitDepth;
+		channels = channelIn == ChannelIn.Mono ? 1 : 2;
 		int bitRate = audioRecorderOptions.BitRate;
 		int numChannels = (int)audioRecorderOptions.Channels;
 
@@ -124,10 +124,22 @@ public Task StartAsync(string filePath, AudioRecorderOptions? recordingOptions =
 			}
 
 			// Create MediaRecorder
-			mediaRecorder =
-				new MediaRecorder(Platform.CurrentActivity
-					.ApplicationContext); //needs context, obsoleted without context https://stackoverflow.com/questions/73598179/deprecated-mediarecorder-new-mediarecorder#73598440
-
+			if (OperatingSystem.IsAndroidVersionAtLeast(31))
+			{
+				if (Platform.CurrentActivity?.ApplicationContext is null)
+				{
+					throw new FailedToStartRecordingException("Android ApplicationContext is null");
+				}
+
+				//needs context, obsoleted without context https://stackoverflow.com/questions/73598179/deprecated-mediarecorder-new-mediarecorder#73598440
+				mediaRecorder =
+					new MediaRecorder(Platform.CurrentActivity.ApplicationContext);
+			}
+			else
+			{
+				mediaRecorder = new MediaRecorder();
+			}
+
 			mediaRecorder.Reset();
 			mediaRecorder.SetAudioSource(AudioSource.Mic);
 			mediaRecorder.SetOutputFormat(outputFormat);

src/Plugin.Maui.Audio/AudioRecorder/AudioRecorder.windows.cs

@@ -11,7 +11,7 @@ partial class AudioRecorder : IAudioRecorder
 	string audioFilePath = string.Empty;
 
 	public bool CanRecordAudio { get; private set; } = true;
-	public bool IsRecording => mediaCapture != null;
+	public bool IsRecording => mediaCapture is not null;
 
 	AudioRecorderOptions audioRecorderOptions;
 	static readonly AudioRecorderOptions defaultOptions = new AudioRecorderOptions();
@@ -56,7 +56,7 @@ public async Task StartAsync(string filePath, AudioRecorderOptions? options = nu
 			CanRecordAudio = false;
 			DeleteMediaCapture();
 
-			if (ex.InnerException != null && ex.InnerException.GetType() == typeof(UnauthorizedAccessException))
+			if (ex.InnerException is not null && ex.InnerException.GetType() == typeof(UnauthorizedAccessException))
 			{
 				throw ex.InnerException;
 			}
@@ -152,7 +152,7 @@ async Task InitMediaCapture(MediaCaptureInitializationSettings settings)
 
 	public async Task<IAudioSource> StopAsync()
 	{
-		if (mediaCapture == null)
+		if (mediaCapture is null)
 		{
 			throw new InvalidOperationException("No recording in progress");
 		}

src/Plugin.Maui.Audio/AudioStreamer/AudioStream.macios.cs

@@ -46,7 +46,7 @@ public Task Start()
 
 				BufferOperation(() => audioQueue.AllocateBuffer(bufferByteSize, out bufferPtr), () =>
 				{
-					BufferOperation(() => audioQueue.EnqueueBuffer(bufferPtr, bufferByteSize, null), () => Debug.WriteLine("AudioQueue buffer enqueued :: {0} of {1}", index + 1, countAudioBuffers));
+					BufferOperation(() => audioQueue.EnqueueBuffer(bufferPtr, bufferByteSize, null!), () => Debug.WriteLine("AudioQueue buffer enqueued :: {0} of {1}", index + 1, countAudioBuffers));
 				});
 			}
 
@@ -150,11 +150,12 @@ void QueueInputCompleted(object? sender, InputCompletedEventArgs e)
 			// check if active again, because the auto stop logic may stop the audio queue from within this handler!
 			if (Active)
 			{
-				BufferOperation(() => audioQueue.EnqueueBuffer(e.IntPtrBuffer, null), null, status =>
-				{
-					Debug.WriteLine("AudioStream.QueueInputCompleted() :: audioQueue.EnqueueBuffer returned non-Ok status :: {0}", status);
-					OnException?.Invoke(this, new Exception($"audioQueue.EnqueueBuffer returned non-Ok status :: {status}"));
-				});
+				BufferOperation(() => audioQueue?.EnqueueBuffer(e.IntPtrBuffer, null!) ?? AudioQueueStatus.InvalidBuffer,
+					null, status =>
+					{
+						Debug.WriteLine("AudioStream.QueueInputCompleted() :: audioQueue.EnqueueBuffer returned non-Ok status :: {0}", status);
+						OnException?.Invoke(this, new Exception($"audioQueue.EnqueueBuffer returned non-Ok status :: {status}"));
+					});
 			}
 		}
 		catch (Exception ex)

src/Plugin.Maui.Audio/AudioStreamer/AudioStreamer.net.cs

@@ -8,38 +8,43 @@ public partial class AudioStreamer : IAudioStreamer
 	/// <summary>
 	/// Gets whether the device is capable of streaming audio.
 	/// </summary>
-	public bool CanStreamAudio => false;
+	public bool CanStreamAudio => throw new PlatformNotSupportedException();
 
 	/// <summary>
 	/// Gets whether the streamer is currently streaming audio.
 	/// </summary>
-	public bool IsStreaming => false;
+	public bool IsStreaming => throw new PlatformNotSupportedException();
 
 	/// <summary>
 	/// Gets the audio streaming options.
 	/// </summary>
-	public AudioStreamOptions Options { get; } = AudioManager.Current.DefaultStreamerOptions;
+	public AudioStreamOptions Options => throw new PlatformNotSupportedException();
 
 	/// <summary>
 	/// Captured linear PCM audio (raw WAV audio)
 	/// </summary>
-	public event EventHandler<AudioStreamEventArgs>? OnAudioCaptured;
+	public event EventHandler<AudioStreamEventArgs>? OnAudioCaptured
+	{
+		add 
+		{
+			throw new PlatformNotSupportedException();
+		}
+
+		remove
+		{
+			throw new PlatformNotSupportedException();
+		}
+	}
 
 	/// <summary>
 	/// Start streaming audio to <see cref="OnAudioCaptured"/>.
 	/// </summary>
 	/// <returns>A task representing the asynchronous operation.</returns>
-	public Task StartAsync()
-	{
-		return Task.CompletedTask;
-	}
+	public Task StartAsync() => throw new PlatformNotSupportedException();
 
 	/// <summary>
 	/// Stop streaming.
 	/// </summary>
 	/// <returns>A task representing the asynchronous operation.</returns>
-	public Task StopAsync()
-	{
-		return Task.CompletedTask;
-	}
+	public Task StopAsync() => throw new PlatformNotSupportedException();
 }

src/Plugin.Maui.Audio/Plugin.Maui.Audio.csproj

@@ -70,7 +70,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="all" IsImplicitlyDefined="true" />
-		<PackageReference Include="Microsoft.Maui.Controls" Version="$(MauiVersion)" />
+		<PackageReference Include="Microsoft.Maui.Controls" Version="9.0.0" />
 	</ItemGroup>
 
 	<!-- Package additions -->