Question

我有一个应用要从一个很旧的版本更新为Android Pie。当用户按下侧键时，它会响应电话铃声音量的变化。我的代码如下。我的targetSdkVersion是28

我有两个硬件设备。在棉花糖Galaxy S3上，一切正常，但是在Pie Pixel 2设备上，有时在更改铃声音量和内容查看器收到onChange调用之间会有很长的延迟。将振铃器从打开切换到关闭时，延迟通常约为5秒，但有时可能会超过30秒。通常，从铃声关闭到铃声打开会更快。

这可能导致什么？

public class VolumeService extends Service
{
    private VolumeService.VolumeContentObserver observer = null;
    private static Notification notification = null;
    private static int notificationID = 1;
    @Override
    public void onCreate()
    {
        super.onCreate();
        observer = new VolumeService.VolumeContentObserver( this );
        Intent mainIntent = new Intent( this, MainActivity.class );
        mainIntent.setFlags( Intent.FLAG_ACTIVITY_CLEAR_TASK );
        Notification.Builder builder = new Notification.Builder( this )
                .setContentTitle( getString( R.string.notification_title ) )
                .setContentText( getString( R.string.notification_text ) )
                .setSmallIcon( R.drawable.ic_audio_vol )
                .setContentIntent( PendingIntent.getActivity( this, 0, mainIntent, 0 ) );
        if ( Build.VERSION.SDK_INT >= Build.VERSION_CODES.O )
            builder.setChannelId( getString( R.string.channel_id ) );
        notification = builder.build();
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        observer.register();
        startForeground( notificationID, notification );
        return START_STICKY;
    }
    @Override
    public IBinder onBind( Intent intent )
    {
        return null;
    }
    private class VolumeContentObserver extends ContentObserver
    {
        private Context context = null;
        VolumeContentObserver( Context context )
        {
            super( new Handler() );
            this.context = context;
        }
        void register()
        {
            context.getApplicationContext().getContentResolver()
                    .registerContentObserver( android.provider.Settings.System.CONTENT_URI, true, this );
        }
        @Override
        public void onChange(boolean selfChange)
        {
            super.onChange( selfChange );
            Log.d("VolumeService", "volume changed");
        }
    }
}

Answer 1

I found that in some devices, you didn't receive volume_ring or volume_music changes in ContentObserver. You need to use a broadcast receiver with intentFilter RINGER_MODE_CHANGED_ACTION. I think pixel uses this broadcast receiver also.RINGER_MODE_CHANGED_ACTION is used to identify the modes of volume like silent, loud etc also.

refer this link also

长时间延迟接收音量更改通知

1 个答案: