问如何判断MediaElement是否正在播放？

EN

// Two converters used with the visibility binding
<Window.Resources>
    <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
    <local:InvertableBooleanToVisibilityConverter x:Key="InvertableBooleanToVisibilityConverter"/>
</Window.Resources> 

// Need to make sure we add loaded behaviour or it will crash app
<MediaElement Name="mePlayer" 
                  LoadedBehavior="Manual" 
                  Source="C:\Users\SamG\Downloads\ZW_20160102_064536A.avi"/>


<Button Content="Play" Name="Play" Click="Play_OnClick" Visibility="{Binding ElementName=mainWindow, Path=IsPaused, Converter={StaticResource BooleanToVisibilityConverter}}"/>
<Button Content="Pause" Name="Pause" Click="Pause_OnClick" Visibility="{Binding ElementName=mainWindow, Path=IsPaused, Converter={StaticResource InvertableBooleanToVisibilityConverter}, ConverterParameter=Inverted}"/>

x:Name="mainWindow"

public partial class MainWindow : INotifyPropertyChanged
{
    private bool _isPaused;

    public MainWindow()
    {
        InitializeComponent();

        mePlayer.Play();
        IsPaused = true;
    }

    private void Play_OnClick(object sender, RoutedEventArgs e)
    {
        mePlayer.Play();

        IsPaused = false;
    }

    private void Pause_OnClick(object sender, RoutedEventArgs e)
    {
        mePlayer.Pause();

        IsPaused = true;
    }

    public bool IsPaused
    {
        get { return _isPaused; }
        set
        {
            _isPaused = value;
            OnPropertyChanged();
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

[ValueConversion(typeof(bool), typeof(Visibility))]
public class InvertableBooleanToVisibilityConverter : IValueConverter
{
    enum Parameters
    {
        Normal, Inverted
    }

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var boolValue = (bool) value;
        var direction = (Parameters) Enum.Parse(typeof (Parameters), (string) parameter);

        if (direction == Parameters.Inverted)
            return !boolValue ? Visibility.Visible : Visibility.Collapsed;

        return boolValue ? Visibility.Visible : Visibility.Collapsed;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return null;
    }
}