How to know the event when `MediaPlayerElement`'s `TimedTextSource` changed

Question

I'm using MediaPlayerElement. Now I need to know the event when TimedTextSource changed. But I can't find any docs.

Answer 1

If you want to detect the event of TimedTextSource switching, you can listen to the PresentationModeChanged event:

// source is MediaSource
var playBackItem = new MediaPlaybackItem(source);
playBackItem.TimedMetadataTracks.PresentationModeChanged += PresentationChanged;

...

private void PresentationChanged(MediaPlaybackTimedMetadataTrackList sender, TimedMetadataPresentationModeChangedEventArgs args)
{
    string currentLanguage = args.Track.Language;
    // do other things...
}

Thanks.