/// <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
{
TaskStarted.Reset();
if (_queueManager != null)
{
QueueManager.TrackChanged -= playList_TrackChanged;
_queueManager = null;
}
_appSettingsHelper.Write(PlayerConstants.BackgroundTaskState,
PlayerConstants.BackgroundTaskCancelled);
_backgroundtaskrunning = false;
//unsubscribe event handlers
_systemmediatransportcontrol.ButtonPressed -= systemmediatransportcontrol_ButtonPressed;
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...");
}
QueueManager.ErrorHandler -= QueueManager_ErrorHandler;
TileUpdateManager.CreateTileUpdaterForApplication("App").Clear();
}