Sometimes I'm getting an exception when trying to get the position of the BackgroundAudioPlayer.Instance. It's happening very rarely, but I've been able to get a StackTrace. The strange thing is, this code is executed every second while playing a track. What could be the cause of this error?
I'm getting this StackTrace.
System.SystemException: HRESULT = 0xC00D36C4 ---> System.Runtime.InteropServices.COMException: Exception from HRESULT: 0xC00D36C4 at
Microsoft.Phone.BackgroundAudio.Interop.IAudioPlaybackManager.get_CurrentPosition() at
Microsoft.Phone.BackgroundAudio.BackgroundAudioPlayer.get_Position() --- End of inner exception stack trace --- at
Microsoft.Phone.BackgroundAudio.BackgroundAudioPlayer.get_Position() at
MC.PodCast.Common.ViewModel.PlayerViewModel.UpdateTrackPosition() at
MC.PodCast.Common.ViewModel.PlayerViewModel.ReactToBackgroundAudioPlayer() at
MC.PodCast.Common.ViewModel.PlayerViewModel.Initialize() at
MC.PodCast.Common.ViewModel.PlayerViewModel.<<get_InitializeCommand>b__5>d__6.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>b__0(Object state)
Of course the code I'm using is just plain simple.
public void UpdateTrackPosition()
{
if (_backgroundAudioPlayer != null && _backgroundAudioPlayer.Track != null)
{
Position = _backgroundAudioPlayer.Position;
}
else
{
Position = null;
}
}
That code is linked to MF_MEDIA_ENGINE_ERR_SRC_NOT_SUPPORTED but I'm guessing that you do have sound.
I have found that the BackgroundAudioPlyer can be very weird. I wrap most of my calls with a "Safe" extension method.
Example
public static PlayState PlayerStateSafe(this BackgroundAudioPlayer source)
{
PlayState state;
try
{
state = source.PlayerState;
}
catch (InvalidOperationException)
{
state = PlayState.Unknown;
}
return state;
}
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