/// <summary>
/// Fires when playlist changes to a new track
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
private void playList_TrackChanged(QueueManager sender, object args)
{
UpdateUvcOnNewTrack();
_appSettingsHelper.Write(PlayerConstants.CurrentTrack, sender.CurrentTrack.Id);
if (ForegroundAppState != ForegroundAppStatus.Active) return;
//Message channel that can be used to send messages to foreground
var message = new ValueSet {{PlayerConstants.Trackchanged, sender.CurrentTrack.Id}};
BackgroundMediaPlayer.SendMessageToForeground(message);
}
/// <summary>
/// Handles background task cancellation. Task cancellation happens due to :
/// 1. Another Media app comes into foreground and starts playing music
/// 2. Resource pressure. Your task is consuming more CPU and memory than allowed.
/// In either case, save state so that if foreground app resumes it can know where to start.
/// </summary>
private void OnCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
{
// You get some time here to save your state before process and resources are reclaimed
Debug.WriteLine("MyBackgroundAudioTask " + sender.Task.TaskId + " Cancel Requested...");
try
{
if (_queueManager != null)
{
QueueManager.TrackChanged -= playList_TrackChanged;
_queueManager = null;
}
_appSettingsHelper.Write(PlayerConstants.BackgroundTaskState,
PlayerConstants.BackgroundTaskCancelled);
_backgroundtaskrunning = false;
//unsubscribe event handlers
_systemmediatransportcontrol.ButtonPressed -= systemmediatransportcontrol_ButtonPressed;
_systemmediatransportcontrol.PropertyChanged -= systemmediatransportcontrol_PropertyChanged;
BackgroundMediaPlayer.Shutdown(); // shutdown media pipeline
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString());
}
if (_deferral != null)
{
_deferral.Complete(); // signals task completion.
Debug.WriteLine("AudioPlayer Cancel complete...");
}
}