public MainPage()
        {
            InitializeComponent();
            _songList = new SongListPage(this);

            if (Device.RuntimePlatform == Device.UWP)
            {
                _audioPlayer = new AudioPlayerUWP()
                {
                    Volume = volumeSlider.Value
                }
            }
            ;
            else if (Device.RuntimePlatform == Device.Android)
            {
                _audioPlayer = new AudioPlayerAndroid()
                {
                    Volume = volumeSlider.Value
                }
            }
            ;
            else
            {
                throw new NotImplementedException("Your OS is not yet supported by this app!");
            }
        }
 public FolderPage(SongListPage parent)
 {
     InitializeComponent();
     _parent           = parent;
     _currentDirectory = _currentDirectory ?? _defaultDirectory;
     GetDirectories();
 }