无法在 android 中按下蓝牙按钮

Question

I am no longer able to determine what button was pressed from any of my bluetooth devices.

GetParcelableExtra returns null for KEY_EVENT in MEDIA_BUTTON intent callback.

This method was working for months, but then suddenly started returning null on GetParcableExtra.

How can I get the bluetooth button event from a background service in xamarin?

    namespace foo
    {
        [Service]
        class BackgroundService : Service
        {
            [return: GeneratedEnum]
            public override StartCommandResult OnStartCommand(Intent intent, [GeneratedEnum] StartCommandFlags flags, int startId)
            {
                registerMediaButtons();
                
                return StartCommandResult.Sticky;
            }

        private void registerMediaButtons()
        {
            var am = (AudioManager)this.GetSystemService(AudioService);
            var componentName = new ComponentName(PackageName, new MyMediaButtonBroadcastReceiver().ComponentName);
            #pragma warning disable CS0618 // Type or member is obsolete
            am.UnregisterMediaButtonEventReceiver(componentName);
            am.RegisterMediaButtonEventReceiver(componentName);
            #pragma warning restore CS0618 // Type or member is obsolete
        }

        [BroadcastReceiver]
        [IntentFilter(new[] { Intent.ActionMediaButton, Intent.ActionHeadsetPlug, AudioManager.ActionAudioBecomingNoisy })]
        public class MyMediaButtonBroadcastReceiver : BroadcastReceiver
        {
            public string ComponentName { get { return Class.Name; } }

            public override void OnReceive(Context context, Intent intent)
            {
                if (intent.Action == Intent.ActionMediaButton)
                {
                    var keyEvent = (KeyEvent)intent.GetParcelableExtra(Intent.ExtraKeyEvent);

                    if (keyEvent == null)// always null now
                        return;

                    if (keyEvent.KeyCode == Keycode.Headsethook)
                    {
                        if (keyEvent.Action == KeyEventActions.Down)
                        {
                            
                        }
                    }
                }
            }
        }
    }
}

Answer 1

The method public T getParcelableExtra (String name) was deprecated in API level 33. That is why you may not be able to use this method.

It provided the new method public T getParcelableExtra (String name, Class<T> clazz) and you can use this. You can refer to the new getParcelableExtra .

In addition, I found the Q&A about Xamarin C# alternative toGetParcelableExtra .